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> M70 22 250 advice
M70 22 250 advice
@ 09:45 pm (GMT) |
markI got a used Winchester M70 22 250 recently and I am a little disappointed with its accuracy thus far. I have Nathans books & have some idea of what I should try next but I'm very open to any suggestions or advice please, here's the situation...I estimate it to be a mid - late 1990s production, its in excellent condition for age, minimal wear on any parts, perhaps had a few hundred rounds through it since new, no rust or pitting I can see. It has an hs precision stock with ali bedding blocks and a heavy 26 inch varmint barrel 1-9 twist. A bushnell XLT 6-18x50 scope. The trigger appears to be tuned as it is light & crisp. I'm not sure if they came out with the glue gun style bedding but it has that...looks a bit rough but i'll see how it goes. The previous owner tells me it can shoot half MOA with 34.5g 2206H behind 55g vmax's. When it arrived the barrel was very dirty, first run with the cleaning rod my heart sank, firm pressure required to 2/3 of the way then easy for a couple inches then firm again. However after 2-3 more runs like this it smoothed out and I had consistent pressure on the rod for the length of the barrel. I also noticed a couple fine marks on the crown (which is a target one) bore junction... possible concern. Next I loaded up a bunch of 55g vmax with 2206H to find no real sweet spot between 34g-35.6g (apparently it shot 1/2 MOA with 34.5g though with different primers) there wasn't really many nice triangular groups either though worst groups were still under 1.5 inch at 100m. I decided to try some W760 since I had some in the cupboard, this seemed better I got a 3/4 inch group but they lined up side by side touching but it doesn't seem to be double grouping from one side to the other. I may be jumping the gun here before I have experimented sufficiently but something doesn't seem quite right, between the bedding, rough barrel to start and crown marks I am not sure what to look into first, I have high expectations of this rifle. I can shoot half MOA with my bedded 7mm rem mag so I shouldn't have any issues attaining the same or better with this rifle. I thought perhaps I should try lapping the bore first, then try working up some loads again, if no improvement get it recrowned & try again... then proper FL bedding. Any other suggestions? |
Replies
@ 10:55 pm (GMT) |
Bryan WebsterRe: M70 22 250 advicePersonally, I would start by completely cleaning the barrel of all carbon, then go ahead and clean all copper from it before doing much else.If you have bought Nathan's books, then consider doing so. The one on accurizing and maintenance would be very useful to you with this rifle. I would also have a very close read on Nathan's instructions as to properly epoxy bed the Model 70 action and tend to that as well before searching for an accuracy load. Optionally you could also have a reputable gunsmith do the bedding work for you as well as repair any issues at the muzzle. |
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@ 11:16 pm (GMT) |
mark sucklingRe: M70 22 250 adviceThank you Bryan. What do you recommend for carbon removal and copper removal? I have used hoppes until it came out clean followed by boretech eliminator (the regular one not copper specific). There was a hint of blue still with the boretech after many runs so I guess I should try a more aggressive copper remover.Yes I have Nathans collection of books, and I have been re reading the appropriate sections, I'm happy to do the bedding but I wanted to prove the barrel was good first after having those initial concerns of its condition. |
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@ 02:55 pm (GMT) |
Bryan WebsterRe: M70 22 250 adviceThere is a section in the book Accurizing and Maintenance that tells you how best to get carbon out. I would refer to that. |
@ 08:39 pm (GMT) |
Nathan FosterRe: M70 22 250 adviceHi Mark, the existing glue gun bedding should be OK for testing for now. But do inspect everything. Like you say, establish a base line first and try to get down to around .75" with consistency.Possibly only one bolt lug touching so check this too. Yes, work through the factors you mentioned and as per Bryans suggestions. Clean it right out, then work on the throat, then the extent of the bore but without raising the finish too high. Make sure the middle screw is set loose, only enough torque to keep the trigger guard in place. The action will flex and cause problems if you over tighten this. Use Loctite to retain it. Full length bedding will help with this later. As long as your hand loads are concentric and the brass is of a good temper, you should be able to set about making optimal ammo. However, please consider experimenting with the 60gr V-Max. It will suit the 1:9 twist well and its slightly longer bearing surface will help if the bore has uneven internal dimensions. Yours should also handle the 75gr A-Max well. |
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@ 11:59 pm (GMT) |
markRe: M70 22 250 adviceThanks Bryan and Nathan. I really appreciate your input.Gives me a few things to work on. Cheers Mark |
@ 12:27 am (GMT) |
Ben GradyRe: M70 22 250 adviceHi MarkI am no expert in gun accurising by any means but I had a new barrel on my 25 06. It was not grouping at all and I didn't know what was up. One of this forums members that lived close by had a look at the rifle for me and saw a tooling scratch mark near the muzzle. So my local gun smith docket the barrel 15mm and re-crowned it. Took it to the range and it grouped straight off. Problem solved for $30.00. I think re-crowning is an inexpensive way to start eliminating possible causes of inaccuracy. Other members please chip in, if I am off track. cheers Ben |
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@ 12:39 am (GMT) |
markRe: M70 22 250 adviceThanks Ben, that's definitely on the cards.Ive given the rifle a thorough clean, got all the copper out & I'm ready to give it a polish now. I've discovered the joys of trademe rifle purchases!, while I was cleaning it I thought id check the twist rate......it appears to be a garden variety 1:14 twist not 1:9 which I was told by the previous owner. That will effect my projectile choice a bit. Thanks again for the input guys. |
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