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Bitten by the Medium Bore Bug

23 Jan 2018
@ 08:03 pm (GMT)

Luke Lahdenranta

As the title says, after reading Nathan's medium bore write ups far too many times I've been bitten hard by the 'need' to own and experience a true medium bore. If I am truly honest with myself, I certainly can't say my trusty 30-06 has ever let me down especially now using the Knowledge base and book series to get the best out of the Grand Old 30-06... but you know want versus need and all that. And hunting moose/elk or deer in Grizzly bear country here in BC does furnish a handy excuse to get into a medium bore...

My head says the most sensible idea and most straight forward path to a medium bore would be to get either a 35 Whelen or a 9.3x62 Mauser. We have a dealer here in Canada that has a good stock of the Zastava M70 Mauser in left handed (which is rare) in either 9.3x62 or 375 H and H if I wanted to go that route.

But the cartridge that has most interested me is the 358 Norma. The 35's have always interested me and while I was initially leaning towards the 35 Whelen, I am kind of intrigued by the possibility of the big Norma mag and the potential power on tap, if I wanted to take it. I reason I could always load it mild to start at the 35 Whelen ballistics and go up from there. I guess I am just really intrigued by the idea of trying for that X factor or Wow! Factor with running something big(gish) and fast(ish) like with the 358 Norma mag. Plus from what I tell from the medium bore write ups the 35 caliber still has the most broad variety of bullets compared to either the 9.3 or 375s thanks to all the slower 35 cal cartridges. The same dealer we have here is also a Norma dealer and has both factory Norma ammo as well as brass and Norma bullets available.

So what I am asking is if I go with the more exotic choice of building a 358 Norma, I want to build it smart and useful while staying at a reasonable budget. Being left handed would my best choice be buy a lefty Remington M700 in 300 Win mag for the donor rifle? That should be a straight forward re-barrel to 358 Norma right? I am thinking start with a semi varmint weight 26" barrel with a 1 in 12 twist and add a Boyds laminate stock and an after market trigger? This should be decent for recoil management and reasonable weight for a target weight of about 9.5-10 lb or so with a standard 2.5-10x42 or so scope on it.

Anyone run a 358 Norma mag? What do you think, worth to build? Would this be a good start to planning my first DIY custom rifle build?

Thanks in advance

Replies

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24 Jan 2018 @ 01:12 am (GMT)	Quote this Paul Leverman Re: Bitten by the Medium Bore Bug Luke - my thoughts are you could go either way. If you were to buy the factory model, you can always outfit it at a later date, when you are ready. Shoot out the barrrel, then when you re-barrel it, put the stock on it. You can do the trigger any time you want. If it's totally abysmal, make it the first piece added. A custom trigger is a gun saver. If, for whatever reason, it ends up you don't like the gun/calibre choice, you can always sell it and it's easier to sell factory than custom. Custom builds are wonderful. Everything you think you want is there, until something doesn't work for you. Barrels aren't usually a problem, they can always be altered to fit another build, later. Stocks, not so much. Most aftermarket stocks are great, but there are duds, and you won't know until you shoot it. Problem is, if it doesn't fit you, or you just don't like it, it's pretty well a stick. Personally, I would do the customized factory. This would get you up and shooting right away. As you learn your rifle, you will find what needs to go first, and while you are waiting, you are still hunting/shooting. With either choice, you get a new rifle. Nothing wrong with that.
24 Jan 2018 @ 01:21 am (GMT)	Quote this Paul Leverman Re: Bitten by the Medium Bore Bug You also picked a good time to start thinking about this. The Kamloops gun show is coming soon, and I'm sure if you looked around, you will find your donor for a reasonable price, maybe. Lately it seems that all the used guns are more than new ones, for some reason. I was talking yesterday to a 'smith who shut down his shop. He still has some rifles/actions left (a nice Sako 85 he's saving for me), I can ask about a donor or complete rig if you want. No guarantees, of course, he's been selling off for a while now. Left-handed. Correct?
24 Jan 2018 @ 01:23 am (GMT)	Quote this Paul Leverman Re: Bitten by the Medium Bore Bug Fat fingers - Sako 75
24 Jan 2018 @ 08:08 am (GMT)	Quote this Nathan Foster Re: Bitten by the Medium Bore Bug Hi Paul, I nearly fell off my chair when you said 85, good to see the correction. Luke, this would ffit on a Ruger 77 if you can find one cheap. A Boyds M77 stock would be fine. The basic 375 Ruger is another route. There really are lots of options here as you do not need an extremely long magazine. But if you can find a left hand M700, that would of course be wonderful. As for recoil, Steph has been shooting the Norma in a horrid WBY monte Carlo stock and finding it quite fine. A straight stock would really tame it. Thats about all this needs, no brakes etc. And yes, this one is easy to download, no dirty habits. Forum member Thomas Kitchen mentioned wanting a 35 RUM Wildcat. I see no major issues with this either, a fairly straight forwards wildcat. Bullet choice is the key, matching the pill to the job at hand. But again, this could be downloaded as can my 9.3 RUM and the .375 RUM. As you suggest, power on tap can be very useful, especially for cross valley work.
24 Jan 2018 @ 09:33 am (GMT)	Quote this Martin Taylor Re: Bitten by the Medium Bore Bug I think your Ideas on contour and weights are spot on Luke! I got bitten by the same bug years ago, also moving up from my trusty 06, ending up with a 9.3X62 Tikka T3 SS which is bedded into a Boyds classic with a VXR on top. Overall l still say it is to light for the calibre. In the field whilst stalking its a hand full though still very accurate, a semi varmint contour would have been a big plus. If the cost of building becomes an issue another factory option may be a L/H Tikka T3X Varmint in 9.3mm.
24 Jan 2018 @ 10:46 am (GMT)	Quote this Thomas Kitchen Re: Bitten by the Medium Bore Bug HI Luke You got to be very careful around this Nathan character, had a brief conversation with him once and now I own a 35/303 but man oh man is it great fun. Down loaded is easily done my cast bullet friend has recently brought a 358 mold so I'm currently playing around with cast bullets with trail boss, once his sizing die turns up and they are properly I'll be changing powder and driving them around 1800fps. Think you have got the right idea you just can't go wrong with a Remington action The other two calibers mentioned are good options specially for factory rifles from what I can workout and I'm sure Nathan will correct me if the great advantage of the 35 bore is the light weight low s.d projectiles on offer, it gives it plenty of versatility if you plan on hunting lighter weight game. All I can say is 200grain ftx on goats have a wow factor. As Nathan mentioned a 35 rum would be great fun and can be down loaded etc it would use raw power instead of bc kinder like the 257 weatherby does, will just have to make sure the twist rate is optimum for local game weight. I saw bergara offer a 375 h&h in a factory rifle but not sure if they have left hand option yet.
24 Jan 2018 @ 01:26 pm (GMT)	Quote this Luke Lahdenranta Re: Bitten by the Medium Bore Bug Thanks for all the reply so far! Lots of direction a guy can go with a medium bore even though shooting left handed limits the options somewhat. I will put the Ruger m77 lefty on the list to keep am eye out for, I do see them turning up. In fact I seen a lefthanded Ruger 375 once but passed on it, the 20" barrel sure looked handy but I'm not sure I can afford any more hearing loss! If I can talk myself off the medium bore cliff edge, I may still put some money into my trusty 30-06. It's a Tikka M695 lefty and as I said has always been good to me. I could save some $$ instead of buying a whole new rifle to start again with and buy the Tikka a real treat like an upgrade to a McMillan stock. That would be quite a makeover for the old boy and I could still in 3 or 5 years if I really want to, have it rebarreled to 35 Whelen... so that's still an idea. But the lure of a new rifle still remains and if I get myself a Remington M700 SPS in 300 Win Mag as a donor rifle, I could even make the mistake of shooting it first... it could actually shoot well and then I'd be in a quandary. But far worse things could happen to a guy then ending up with a 300 Winchester... :) Still, I got a big of time here to plan. I will be turning 40 in a bit over a year. So I'm selling this idea to my wife as a 'mid life crisis rifle' far cheaper than a sports car!! :)
24 Jan 2018 @ 04:51 pm (GMT)	Quote this Trace Jacoby Re: Bitten by the Medium Bore Bug Luke, You are a man after my own heart. I have been bitten by the same bug. I had bought a used Remington M700 in 30-06 with the intent of building a Whelen, but now you have me rethinking the 358 Norma. I will be interested to see which route you take and how it works out. Trace
24 Jan 2018 @ 05:46 pm (GMT)	Quote this Peter Bjerregaard Re: Bitten by the Medium Bore Bug I can only recommend the .358 NM. I read Nathan's articles, talked to Nathan, and suddenly I found a Husqvarna 1651 in .358 NM. Price was absolutely right as nobody knows it here in Denmark and ammo is very expensive (only offering Norma Oryx at around $20/round). Straight custom stock, but light 24" barrel. Everybody thought I was mad:'You can't shoot that - recoil is massive'. Well, it isn't. It's a pussycat on steroids. You need proper technique but otherwise no problems - even prone. Now I have to admit my lack of trust. I didn't fully trust Steff and Nathan. So I started of with 200 gr FTX (anyone for 80 bullets?). And I bought training wheels - suppressor. Don't really use it. Good luck, you can't go wrong.
25 Jan 2018 @ 04:33 pm (GMT)	Quote this Luke Lahdenranta Re: Bitten by the Medium Bore Bug After asking around here what typical gunsmith rates are, I have to say doing up a custom rifle in 358 Norma (or any caliber for that matter) will be a bit more expensive than I first thought. I had hoped that it could have been done for under $2000 including the donor rifle but that sounds unrealistic. Since the quotes for just a rebarrel run about $900-1200. It looks like a budget of about $2200-2500 plus the donor rifle/action would be much more realistic. Since I don't actually have a donor action ready I think I may for now look at some different options... The Zastava M70 LH 9.3x62 for $795 or 375 H and H for $895 look pretty attractive right now. Especially with the same dealer selling the Privi PPU ammo for $29.95/20 CAD that's seems a pretty good price. Only thing is that is a pretty slow load at about 2250 fps in the 9.3. Like a big 30-30... I wonder how much better of a Mule deer/Elk load that would be over my fully optimized 30-06 running something like a 220 gr Woodleigh at 2500 fps? I'm sure the bullet weight and diameter count for something over the 30-06 but I'm not sure how much. Like I said the other option is dressing up my old 30-06 with a new McMillan stock makeover that would run about $8-900 CAD delivered same price as a new Zastava. Hmm choices, choices.
26 Jan 2018 @ 09:55 am (GMT)	Quote this Nathan Foster Re: Bitten by the Medium Bore Bug Hi Luke, the difference between the two loads you mention will not be much, not at those velocities. Wounds will appear much the same, one as a result of frontal area, the other via velocity. You have to trust your instincts in this because they are correct. The example you have given is the sort of thing I see a lot, it becomes a fad, the guns ending up back on auction, round and round they go. Having said this, good hand loads help bring out greater potential from the 9.3. The one thing I want to say to you, is get the power level that you really want. Don't cut yourself short. Regarding the .375 Zastava, please check the magazine length. You'll want at least 3.6" mag space. Don't cheap out on yourself and go with something that might be OK now, but cause frutrations later on if you feel like widening your experiments. If if you want something short, compact and cheap, consider the .375 Ruger, then put time into DIY accurizing. Regarding Prvi, I have had a good run with it over the years. It is often underloaded and some instances unethical for killing (e.g 243 at distance) but its a good way to obtain brass in some calibers. In any case, I have a batch of ammo here at present with paper thin primers. Even with a firing pin 10 thou shorter than the usual minimum, the firing pin punches straight through, blasting gas back into and through the action. I have not seen this before, only heard of it but had no means to test for myself. So to all, please wear safety glasses when testing factory ammo bearing the NNY head stamp. Take things slowly Luke, bit by bit. Allow ideas to perculate and so forth.
26 Jan 2018 @ 01:35 pm (GMT)	Quote this Lane Salvato Re: Bitten by the Medium Bore Bug Luke, If I can recommend something, read the second paragraph in Nathan's last post and commit it to memory. I wanted a custom 35 Whelen so bad and ended up letting a gunsmith pressure me into a 338-06. It was a good rifle but it did not have the bullet diameter or power level I was looking for. It was what the gunsmith wanted to build, not what I wanted to buy. Nobody else earned the money you are using to purchase your rifle so nobody else should pressure you. Eventually I had that rifle re-chambered to a 338 Win. Mag. It shoots very nicely and Nathan is helping me learn to develop loads with large, heavy 338 projectiles. I'm happy now with this rifle but I regret not just getting what I wanted originally. I like the 35 bores, especially the 35 Whelen. I wish I would have gotten it. One day I will have one but it will be awhile. For what I spent re-tooling the 338-06 to the 338 Win. Mag I could have used to get an even nicer 35 Whelen originally. We live and we learn. Unfortunately sometimes we learn more from our mistakes. Some may say I'm too much of a Foster Fan, maybe a Foster Fanatic,but in my experience if Nathan likes what you like then you've got a winner. He's a man you can trust.
27 Jan 2018 @ 03:29 pm (GMT)	Quote this Luke Lahdenranta Re: Bitten by the Medium Bore Bug Thanks again for the very good replies. Continuing to think things over, I think that regardless of which direction I end up going with I do want a bit of reach and a reasonably flat trajectory out to 300 or maybe 350 yards. I have had some fill with some close range thumper in my lever guns but for this rifle I really don't want to it be 'just' a close range thumper. It is nice to have at least one rifle with a bit of reach and some thump, just for versatility. In thinking about what Nathan wrote, I think I will take a good hard look at the basic Ruger 375. While I still like a lot of what the 358 Norma (and the 35's) bring to the table with a good selection of light and cheap bullets plus the 357 pistol bullets (how can you beat that for trigger time?)but to borrow the old saying... "a Ruger on the gun store shelf is worth two fantasy custom builds in the bush". My thanks again for all your thoughts.
29 Jan 2018 @ 03:38 am (GMT)	Quote this Kenneth Kephart Re: Bitten by the Medium Bore Bug The 358 version of the Ultra Mag here in the States is known as the 358 UMT( Ultra Mag Towsley). Designed/developed by writer/smith Bryce Towsley. While not SAAMI approved it is a widely known wildcat. Along with the 416 UMT. Performance is reported to be impressive.
30 Jan 2018 @ 07:33 pm (GMT)	Quote this Luke Lahdenranta Re: Bitten by the Medium Bore Bug So I have been able to confirm that the Zastava 375 H and H is not built on a true magnum length action but a modified standard length Mauser action and it sounds like the magazine length is 88 mm? That sounds short since the max COAL for the 375 H and H is 92 mm or 3.6"... I think I will steer clear of this option. Has anyone ever run the 35 Whelen AI ? Worthwhile velocity increase over the standard Whelen? I'm thinking that if I could run the 225 gr Sierra up to about 2700-2750 fps then I would be happy. It sounds like the standard Whelen is right on the fence for that velocity. I found this Speer load data posted online, and the Whelen data looks pretty potent with some newer powders, the Speer 250 gr to 2700 fps and the 220 gr FP to 2800 fps. But I don't know if this data is magic pixie dust and unachievable for us Meer mortals... https://www.speer-ammo.com/en/reloading/rifle Scroll down for the 35 Whelen loads.
31 Jan 2018 @ 12:19 am (GMT)	Quote this Warwick Marflitt Re: Bitten by the Medium Bore Bug Luke read about the 35 Whelen & AI in the cartridges section unless you have already. https://www.ballisticstudies.com/Knowledgebase/.35+Whelen.html
31 Jan 2018 @ 09:20 am (GMT)	Quote this Luke Lahdenranta Re: Bitten by the Medium Bore Bug I just want to correct the above post, the Zastava 375 magnum has the magazine box modified to 3 3/4" or 95 mm, not 88mm. That shorter measurement probably refers to the standard (30-06, 7x57 etc) length box. The longer 3 3/4" box sounds much more reasonable for the 375 magnum!
01 Feb 2018 @ 11:30 am (GMT)	Quote this Thomas Kitchen Re: Bitten by the Medium Bore Bug HI luke Thought I would just mention that there is the wildcat 35/300wsm, It would fit in a left hand tikka fine just need to get the appropriate barrel weight. 95mm sounds manageable for mag length, we are lucky Nathan normally talks coal in the knowledge base so we can check things.
01 Feb 2018 @ 01:58 pm (GMT)	Quote this Nathan Foster Re: Bitten by the Medium Bore Bug Yes, that's plenty of length Luke. Thanks for looking into this, it will be of benefit to other readers here. Much appreciated.
01 Feb 2018 @ 02:07 pm (GMT)	Quote this Nathan Foster Re: Bitten by the Medium Bore Bug Sorry- just be careful with that type of load data. A lot of it is untested, computer generated. The throats vary a good deal on the Whelens and AI's so its hard to say how fast each might go. The velocities I gave here on the site are realistic. If you really want high power, opt for a large case size, that's the key. Its a bit like the old .280 and AI versus the Rem Mag and folk trying to beat physics. Sometimes you'll fluke it, cheat things via a loose bore .280 and a very long barrel, but most other times, the Rem Mag simply beats the smaller case by a good margin. But then we have to compare apples with apples and not slow figures such as 2960fps for the Rem Mag versus a primer popping .280 load.
10 Feb 2018 @ 06:09 pm (GMT)	Quote this Luke Lahdenranta Re: Bitten by the Medium Bore Bug I just thought I'd share a few things I have found as I have continued to research the medium bores, these might prove useful to someone else contemplating a new medium bore rifle. One thing I am learning is that anyway you slice it, if you want to build a custom rifle in a slightly oddball chamber like a 358 Norma Mag is you got to be prepared to pay the piper. A lot more $$ for dies, brass etc plus as the gunsmith informed me I would have to buy my own reamer for about $250 CAD. Sigh the big Norma magnum sure is an expensive date... But still the desire for a 358 Norma remains. I discovered that the old danish firm of Shultz and Larsen is still making them (along with a bunch of other calibers) and even in lefthanded as well! Joy! But they don't actually have a Canadian (or USA) importer yet so again... $$$ I talked to a well regarded lical gunsmith and by far the easiest and one of the cheapest options would be to have my 30-06 caterpillar turned into a 35 Whelen butterfly, a benchmark barrel installed on my Tikka will go for about $1k. I have almost talked myself into going through with it. I think I would really like the Whelen. Nathan's write up on the 35 Whelen is one of his best and most eloquent, I'm certainly sold. The only thing that is giving me pause is finding out just how slim the selection of 35 caliber bullets is here in Canada. I mean it is really sad. One big online dealer, for example lists 12 bullets for 358 caliber, versus over 50 for 338 cal and about 25 for 375 caliber. And to add insult to injury, of the dozen 358 bullets listed, almost half are out of stock... including the Sierra 225 gr btsp and the Speers. Living in the .30 caliber component land of milk and honey that's quite a shock haha. The other option that I am looking closely at is since in order build a 358 Norma magnum, I need a magnum action as a donor anyways. So I could buy as a stepping stone either a 300 mag or maybe a 338 Win Mag to try for a bit then rebore/rebarrel. I may go that route. The other option would be to skip all the intermediate steps in the journey and just fast forward to the 375 Ruger Guide Gun. Nobody starts threads anywhere, anytime, asking if the 300 Mags or the 30-06 or 7mm Mags are as good as the Three Seven Five. It's seems to be almost universally acknowledged that the magnum 375s are a big, you can't mistake it, step up from even the fast .30s :) Anyway, if just reading about and researching the medium bores is proving to be this much fun, then I can't wait to actually get my hands on one!
10 Feb 2018 @ 10:22 pm (GMT)	Quote this Mike R Re: Bitten by the Medium Bore Bug The 338 Win mag I found a little bit underwhelming, certainly a step up from a 30-06 but not quite what I was looking for so I sold it. I would consider doing a 35 Whelen AI, but probably the 375 Ruger is just easier all round. Bullet selection is far better and if you don’t like the recoil you can always download it to make it more comfortable. I have a 45-70 that can be just plain brutal loaded to max, but back it off to where it doesn’t punch you in the face and kick you in the nuts, it’s still very effective. I got a good load around 2100 for a 350gr flat nose and still keep my teeth. Just because it can do it doesn’t mean you have too, just let the wide meplate do the work.
18 Jun 2019 @ 01:15 pm (GMT)	Quote this Luke Lahdenranta Re: Bitten by the Medium Bore Bug So I started this thread about a year and a half ago, when after reading Nathan's medium bore cartridge write ups way, way too many times i found myself bitten by the medium bore bug and just had to get one. I went back and forth on a bunch of different options with a 9.3x62, the Ruger Guide gun 375 and 338 Win mag being the top contenders... But sometimes a good deal is what is needed to break the dead lock so I just ended up the proud new owner of a Weatherby MK V Lefthanded in 340 Weatherby !! More cartridge then I will probably ever need but lots of horsepower here to play with. I dont think I would have gone for the deal but the rifle includes reloading dies and a good bunch of brass so that helps a lot since I can reload for it from the get go. Also I can also just start my reloads low and just go up as my shoulder can stand it... Speaking of recoil my main question right now is what to scope it with since with the recoil of this gun, eye relief is critical and from what I read this is a gun that can be a real scope killer. I have a Sightron SIII 3.5-10x4mm MD that might work, it should be a sturdy scope but the eye relief is 3.6-3.8" so maybe right on the borderline for this gun. I could swap some scopes around and put on either a Leupold 4x or 6x fixed scope since they have well over +4" eye relief, although they may give up a little bit of flexibility being fixed power. Also what scope mounts to use? The gun is equiped with Weaver bases, but as far as I am concerned its an open field, I will buy whatever I need that will be reliable over the long term. Luke
18 Jun 2019 @ 01:19 pm (GMT)	Quote this Luke Lahdenranta Re: Bitten by the Medium Bore Bug oh i meant to add my rifle is stainless one with a more tame looking synthetic stock, it looks more like something Bell an Carlson or HS Precision im not sure if its original. at least iits not the rather wicked looking wood stock model !
19 Jun 2019 @ 06:58 am (GMT)	Quote this Andrew Murray Re: Bitten by the Medium Bore Bug I think whatever mount you end up with, having something that will handle the recoil is important, eye relief also a big factor as you mentioned. What are you going to be using the gun for? As in what range... and then chose the magnification based on that Sounds like a good deal! Post a photo if you can.