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Recently picked up an older rifle with a mauser 98 action in 7x64. Has a butterknife bolt handle and what appears to be a relatively new barrel. Only markings on the rifle are the 7x64 stamp on the barrel. Rifling looked good.Tried some test loads with IMR4350 & IMR 4831 and 160 gr bullets. Groups were terrible (4 inch @ 100). Rechecked the barrel and the crown in particular....nothing wrong. Tried some 150 gr Sierras & groups got a little smaller (3 inch). Now I'm beginning to see why I picked this rifle up so cheap ! So next I try some 140 gr Sierr'a with 4350. First group down to 1 1/4 inch. Played with powder charges and seating dept and now have groups just under an inch. Thought most 7x64's were built with a fast enough twist to handle 175 gr bullets. Any ideas why someone would build a 7x64 with a slow twist ?? | ||
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Built to shoot light bullets fast. There is usually quite a long lead on the 7x64 to shoot the big bullets. What’s the bedding like? | |||
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how about a new barrel appropriately set up? | |||
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Maybe for use in mountains shooting chamois? | |||
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Barnes makes 110 and 120 grain TTSX bullets in 7mm. These may be short enough to stabilize in your rifle, worth a try and despite their light weight will penetrate deep. Somebody I know has put a few 120 grain 7mm TTSX's through cow elk with no difficulty. | |||
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7x64 is meant to shoot long heavy bullets at moderate vels -- classic loading is 173@2800 ish ... though it can shoot lighter bullets faster surprised it doesn't shoot well, though .. my default starting length is -028 to -032 off the rifling, or loaded to cip/sammi length and a middle of the chart load ... then move back a bit, say .005, in steps and see if it improves ... one of my favorite rifles, with a great story, is a soda straw 7x64 that shoots 4 into a little bitty group ... if you try to shoot the 5th one, it's hot and moves into about an inch.. it loves hornady 162 factory loads, btw opinions vary band of bubbas and STC hunting Club Information on Ammoguide about the416AR, 458AR, 470AR, 500AR What is an AR round? Case Drawings 416-458-470AR and 500AR. 476AR, http://www.weaponsmith.com | |||
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You have it shooting under an inch with 140 gr. bullets, whats the problem? Use a BarnesX, GS Customs monolithic or Nosler Accubond or partition...It won't lack for penetration. Then play with the 175s..Try H414 to start with in a 7x57 or 7x64..Keep in mind you probably have a very long throat and may be able to use more powder than the Reloading books call for, go up in 1/2 inch increments to a max load if your a seasoned reloader...Ive found it works on heavy bullets.. Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
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If you haven't measured the twist then how can you conclude the twist is too slow with only the the examples you have? Did you see any evidence of keyholing? Did you shoot at any range longer than (presumably) a hundred yards? There are any number of reasons why some bullets may not shoot well in a particular rifle that have nothing to do with its twist rate. Blaming "too slow" twist has become a knee-jerk reaction to accuracy problems in recent years, but whether your rifle's problems are related to twist can't be determined without further information. Simply writing off the poor performance of certain heavier bullets without definitively determining the cause may sell your rifle short. | |||
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Are barrels cheap where you are? I'd think, if you couldn't sort it out as is, just sell it to someone who doesn't care about heavy bullets. | |||
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Try some european bullets like the classic TIG and your groups are getting smaller - I think, 2800fps with a 175grs bullet is not a moderate velos., it is in the same class like the .30/06 and loaded hotter with european loads than her cousin, the .280Rem. | |||
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This could also be a potential cause of accuracy problems. Many European 7mm barrels have a groove diameter of .286" as opposed to the standard U.S. diameter of .284. If a bullet has a fairly soft jacket and a flat base then it may upset enough to properly fill the grooves of a barrel that is .002" oversized and thus shoot with fair accuracy. A harder bullet or one with a boattail base might not do as well. | |||
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Thanks for all the replies. Where to begin??? I checked the twist and it appears to be 1 in 12 in.So maybe it was set up to shoot lighter bullets. Slugged the barrel and it is very close to .284 so I don't think bore diameter is the problem. Certainly not when the 140 Sierra will group under or around an inch. As Ray said "whats the problem".... 140 gr bullets under an inch will make a pretty good deer rifle. I have a stainless Zastava all smoothed up and it handles heavier bullets just fine so I don't think I'll waste the money on a new barrel. I have a couple 280's that fit in that slot as well. I thought it was strange that a 7x64 was set up with a slow twist And wondered why?? | |||
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Also a 140 gr. Accubond or partition is good elk medicine up to 250 to 300 yards..and your set up beats the 270 with 130 gr. bullets, you have winner and who knows if you play with the long 160 and 175 gr. bullets you sure might find a fitting load..Try some max loads of H414, Good luck... Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
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