Accuracy issues

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pratt2208
Posts: 54
Joined: Tue Mar 29, 2011 11:08 pm

Accuracy issues

Post by pratt2208 »

Hello all,
My father has a 1913 that is 15 years old and has close to 20 cases of ammunition through it. He is starting to have accuracy issues and was thinking about getting it rebarrelled, but someone said it might be his head space is off. Is there any way that a headspace issues would cause his rifle to not group(even with a scope and off a bench). Once the group starts to go astray it is unpredictable and has been causing him to lose multiple points in a single shot. Also the gun is already bedded.

Thank you
Jason
Rover
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Location: Idaho panhandle

Re: Accuracy issues

Post by Rover »

The first thing I would try is a thorough cleaning.
pratt2208
Posts: 54
Joined: Tue Mar 29, 2011 11:08 pm

Re: Accuracy issues

Post by pratt2208 »

The gun is regular cleaned and well taken care of. He doesn't want to spend the money to put the barrel on and have the action be bad.
jhmartin
Posts: 2620
Joined: Mon Nov 29, 2004 2:49 pm
Location: Valencia County, NM USA

Re: Accuracy issues

Post by jhmartin »

Back in May I took my daughter's 1907 action to Lapua in Mesa, AZ to test ammo for her next year in NCAA rifle.
I had 7 team actions to test and went thru quite a few lots of ammo to try and find one that shot in her gun. Of all the ammo lots we just could not find any that shot well .... being able to find good lots for the others made me suspect the barrel.
This barreled action shot well enough for her to win the 2015 NCAA SBR event using STD+ ammo that year ... only a few years ago...
At the end of last year she complained about not calling a lot of shots .... hmmmm, I thought she was "trying to hard", but after that ammo test in May .....

OK, so I called Mark Penrod of Precision and had a new barrel put on. Back to Mesa a week ago and quickly found a lot of ammo that shoots great.

If it is "only" headspacing, well with that action you're can't just reset it as with a 4-bolt action. I think by the time you do all the playing around you can do with it ... re-chambering/headspacing or re-crowning or whatever, you can have a new barrel put on it. Lots of choices ... chat with the gunsmith you would have do it.
Note: I am VERY happy with the new barrel Mark put on my daughter's rifle. Note I had him true & thread the receiver & barrel instead of just pressing it in.
Bryan996
Posts: 100
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Location: Surrey

Re: Accuracy issues

Post by Bryan996 »

pratt2208 wrote:The gun is regular cleaned and well taken care of. He doesn't want to spend the money to put the barrel on and have the action be bad.
Jason if the barrel were to be replaced the gunsmith would reset the headspace when fitting the new barrel (the headspace is the gap between the face of the barrel and the bolt). There is very little that can go wrong with a round Anschutz action so I wouldn't worry about it being bad.

However before you go to the expense of changing the barrel I would give it a very good deep clean with VFG blue paste. This will remove any lead in the barrel by gently polishing it out but won't damage the barrel steel. Then try and arrange a batch testing session from a vice as that will prove how well the rifle groups. If after all that the groups are terrible then go ahead and change the barrel. This was the route I went down.

I would however be very surprised if the barrel was bad in only 10,000 rounds, especially if your father looks after it, Eley's test barrels in the UK have had up to 160,000 rounds through them! My barrel was rubbish as the previous owner hadn't cleaned or used it regularly so it had corroded. I suspect your fathers rifle is just a little leaded up. Use the VFG paste for 2 to 3 hours then see how it performs.

Bryan
Tim S
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Location: Taunton, Somerset

Re: Accuracy issues

Post by Tim S »

Jason,

excessive headspace can cause poor accuracy by impeding ignition. Headspace is typically set to 0.043in, so the rim will be held securely between the bolt and barrel face, without being crushed. Excess headspace prevents the bolt pushing the cartridge fully home, so there is a gap between rim and barrel face. When struck by the firing pin, the case moves forwards, absorbing some of the blow, and potentially delaying ignition. After ignition, the propellant will waste energy expanding the rim back to the bolt. 0.046in is often cited as the point at which the effects become really noticeable, though with the right batch of ammo, accuracy may still be OK; a regular poster on this forum, the late Bart P, recorded competitive accuracy with a headspace of 0.048in!

As Bryan notes headspace is reset when a new barrel is fitted, but if headspace was way out of spec before replacement, there is the risk it will continue to expand with the new barrel. In a rear-locking action like the Anschutz, the bolt body takes some of the force where it meets the handle. Some bolts will gradually flatten slightly though use, so the body becomes shorter, opening the headspace. You can reduce headspace with shims in the bolt, but do you want to do this shelling out for a new barrel?

To check the headspace properly, a set of graduated gauges is preferable to Go (0.043in) and No Go (0.046in) gauges as the 0.03in difference is rather coarse. You'll need to remove the firing pin and extractor claws. If you don't have gauges, or can't borrow a set, take it to a competent gunsmith for assessment. I have a set of graduated gauges made by a machinist friend, and paid for in beer.

Depending on how the rifle has been cleaned, a really though job with JB or VFG paste may be in order, however, the barrel may just be worn. Twenty cases is 100,000 rounds (Bryan misplaced the decimal point), which is about the point many folks report their barrels start to shoot groups a bit bigger than the bull. If you do chose to have it rebarreled, I'd suggest replacing the bolt springs too. Springs are cheap, and it's a good idea to replace these sooner than 15 years anyway.
Cumbrian
Posts: 265
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Location: Hampshire

Re: Accuracy issues

Post by Cumbrian »

[quote="Tim S"]Jason,

excessive headspace can cause poor accuracy by impeding ignition. Headspace is typically set to 0.043in, so the rim will be held securely between the bolt and barrel face, without being crushed. Excess headspace prevents the bolt pushing the cartridge fully home, so there is a gap between rim and barrel face. When struck by the firing pin, the case moves forwards, absorbing some of the blow, and potentially delaying ignition. After ignition, the propellant will waste energy expanding the rim back to the bolt. 0.046in is often cited as the point at which the effects become really noticeable, though with the right batch of ammo, accuracy may still be OK; a regular poster on this forum, the late Bart P, recorded competitive accuracy with a headspace of 0.048in!

Tim,

I seem to have the opposite problem, if it is a problem. I have been using my second 1800 series barrel so as not to have quite a quantity of good, batch tested Lapua Centre X ammo lying idle. I find that the bolt is a little stiff to close, not impossible at all but there is resistance. The results seem o.k., i.e. within the wide limits of my ability and usual scores, though a bit disapppointing even so. But, could there be a problem with the restricted headspace nonetheless?

Roger
Tim S
Posts: 2018
Joined: Mon Jan 03, 2011 11:33 am
Location: Taunton, Somerset

Re: Accuracy issues

Post by Tim S »

Cumbrian wrote:Tim,

I seem to have the opposite problem, if it is a problem. I have been using my second 1800 series barrel so as not to have quite a quantity of good, batch tested Lapua Centre X ammo lying idle. I find that the bolt is a little stiff to close, not impossible at all but there is resistance. The results seem o.k., i.e. within the wide limits of my ability and usual scores, though a bit disapppointing even so. But, could there be a problem with the restricted headspace nonetheless?

Roger
Roger,

PM on it's way to avoid hijacking the thread.

Tim
Cumbrian
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Location: Hampshire

Re: Accuracy issues

Post by Cumbrian »

Tim,

Many thanks.

Roger
mtncwru
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Re: Accuracy issues

Post by mtncwru »

Tim S wrote:If you do chose to have it rebarreled, I'd suggest replacing the bolt springs too. Springs are cheap, and it's a good idea to replace these sooner than 15 years anyway.
I'd start with the springs. Make sure you replace both the spring around the firing pin as well as the spring around the cocking indicator as a set. I'd definitely check that before you start going the new barrel route.
WesternGrizzly
Posts: 278
Joined: Sat Jan 09, 2010 10:43 pm

Re: Accuracy issues

Post by WesternGrizzly »

Tuner. It's the only answer.



But in all seriousness, start with the springs, then the firing pin, then the torque, then the muzzle, then the headspace. I would also suggest using some JB paste on the bore. It usually helps. Also barrels DO wear out. I have like 100k through mine and it is getting close.
Matt
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