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64 MPR Ignition Issues

2K views 24 replies 9 participants last post by  farm boy 
#1 ·
My 64 MPR has 20k rounds through it and it suddenly took a dive performance-wise. About one in five rounds would land one to three inches low ... one a foot. I have been shooting this case of ammo for a month without trouble so I say ignition issues.

Took the bolt apart and there was some obvious roughness on the rear firing pin/striker. I shot all winter down to -25C so I ran it dry. My guess is that was the cause. I polished it about 90 percent smooth with a wire wheel and put it back together. It might be 100 percent now or I might go after it again. I've never done this kind of work before so I was wary of over doing it. Heck, after I got the rear of the bolt apart I had serious doubts I would ever get it back together.

So here are the questions:

1. I have never removed a pin in a firearm before. Is the pin and are the holes uniform size or is there a taper/right and wrong way? I used a finish nail, now I know there is such a thing as a pin punch but they aren't available locally.

2. This is a link to a service kit for this action. All of the parts in the kit are available separately.
Do I want the kit, some parts only, or a kit with additional spares? Keep in mind the action is discontinued.

https://www.nordicmarksman.com/Service-Set-for-Match-64-22LR-Bolt.html

I've only had the rifle for 8 months and I'm completely green so I have no idea what to expect or how long things will go. All advice gratefully received.
 
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#3 ·
One of the things I learned shooting Benchrest, that firing pin springs have a marked effect on precision. Some years ago I bought a 1970 54 Anschutz and had it rebarreled. The smith asked me when did I last change the spring. I didn't know so bought a pack of new ones from Wolf. Before I changed to the new one I shot 15 two shot groups with the old spring, immediately changed the spring and shot 15 more two shot groups with the new spring. Statistics showed that the velocity spread dropped from 36 FPS to 24 FPS at the 99% confidence level and the group size dropped from .219 to .190 at the 77% confidence level which isn't earth shattering but enough that I put in a new spring every year.
 
#4 ·
Thanks gentlemen. It seems pretty reasonable to replace the firing spring at that round count. As a side note I was surprised/disappointed that Anschutz shipped the new rifle with the bolt cocked. Who knows how long that was?

I'm leaning towards getting the complete bolt service kit and an an extra firing pin on top of that. I would hope this stuff is available from Anschutz for a while.
 
#5 ·
Get the parts if they are available, because once gone they are gone they are gone. I know a lot of match 54 owners wish they bought spares parts when they were available.

I wish I kept what I had stored away, sold the parts thinking I was not going to keep shooting Anschutz. I have 2 match 54 with a 3rd coming.:D

Lee
 
#6 · (Edited)
Coming to this a little late, but this sounds more like an ammo issue. An ignition problem with the rifle normally starts as that: poor ignition. Some cartridges don't go bang when you press the trigger. A weak spring, a worn firing pin, excess headspace, a loose trigger, and often accumulated fouling can all be at fault. Poor ignition is often said to cause vertical stringing in groups. But that's not the complsin here. Poor ignition doesn't normally see 20% of shots dropping noticeably low. That sounds more like poor ammo QC, and low charges.

What is the ammo, and is the case all if the same batch no? Coming in the same crate isn't always a guarantee the ammo is from the same batch.

You don't mention maintenance, but how often have you cleaned the barrel in the last eight months.
 
#7 ·
Tim, If you read what Will found on the internal part being rough this will cause an ignition problem. what you described as typical ignition problems with vertical stringing is normally related to just a worn spring.

being the part was rough more than likely it was binding and slowing the forward movement, and then not all the time.
I seen this with Match 54's (pre-1977) especially when using Wolff springs, the spring will bow out when installed on the pin and rub inside the bolt causing erratic pin hit. also because the Wolff springs give a higher rate of pressure they tend to cause the top pin guide to bind against the slot in the bolt.
if a firing pin will not drop freely to the stop when you insert it in the bolt you will not have optimum ignition.

Lee
 
#12 · (Edited)
at around 10k my 452 started throwing fliers. I thought it was clean. then i stumbled on the carbon ring thing. i had to scrub that thing for 4 hours to get it clean. the only thing that i have found to knock down a cold carbon ring is a mix of 2/3-3/4 parts hoppes #9, and 1/4 to 1/3 part kroil. and a 6mm brush. i just keep wet brushing it, let it soak, wet patch, wet brush some more, until the patches starts coming out nasty. i showed this trick to one of my co workers and he was amazed. got his rifle clean with bore tech c4, patches super clean. then i said "watch this", and i was only scrubbing the throat with the hoppes kroil mix and the patches were coming out completely black.

due to the 4 hour ordeal, how i do it now is when they are hot at the range i use a patchworm with patches soaked in ballistol. when hot that gets a lot of the carbon out, so that when i do end up cleaning the throats with the hoppes/kroil mix and a 6mm brush, it doesnt take that much work.
 
#14 ·
at around 10k my 452 started throwing fliers. I thought it was clean. then i stumbled on the carbon ring thing. i had to scrub that thing for 4 hours to get it clean. the only thing that i have found to knock down a cold carbon ring is a mix of 2/3-3/4 parts hoppes #9, and 1/4 to 1/3 part kroil. and a 6mm brush. i just keep wet brushing it, let it soak, wet patch, wet brush some more, until the patches starts coming out nasty. i showed this trick to one of my co workers and he was amazed. got his rifle clean with bore tech c4, patches super clean. then i said "watch this", and i was only scrubbing the throat with the hoppes kroil mix and the patches were coming out completely black.

due to the 4 hour ordeal, how i do it now is when they are hot at the range i use a patchworm with patches soaked in ballistol. when hot that gets a lot of the carbon out, so that when i do end up cleaning the throats with the hoppes/kroil mix and a 6mm brush, it doesnt take that much work.
Hey Clem,

You posted while I was typing. I always clean the rifle as soon as I get home but it is still at or below freezing here so it is cold. I'm going out to the shop right now to look for a ring and regardless what I see I will give it the four hour deal as per your experience. Thanks for the specifics, very informative.
 
#13 ·
I'm shooting prone with bipod and rear bag, free recoil. My set up is extremely steady. When I practice I sometimes line up the shot, put my finger on the trigger and then close my eyes for several seconds. I am usually right on when I reopen my eyes.

I was shooting through a case of SK Pistol Match when this problem came up. I had adjusted my tune for the ammo and then shot for score and groups for eight days. Then I set myself the goal of beating the average which I managed to do bout 2/3 of the time for the next two weeks. At the end I had two days in a row where I got 398, better than I thought this stuff was good for. THEN 393 and 388. That was followed by a day when it was not even worth trying for a score. Then I switched to the Standard Plus that I had data for but it is in trouble too.

As I said earlier, I will go over the bolt again and check/clean the bore and chamber and try different ammo. I'll let you guys know the outcome, thanks for checking back.

Now I know why some of you have so many rifles ... I NEED SOMETHING TO SHOOT!
 
#20 · (Edited)
Probably Solved

Thanks everyone.

Took the bolt apart again and polished the striker and the hole it passes through. Same for the firing pin. Even did some light work on the spring itself. After the initial cleaning of the bore I felt that I could see a carbon ring so the barrel got scrubbed, soaked, scrubbed, soaked, etc. In the end I think I still see it but went out and shot it anyway.

After 10 foulers, the last eight of which grouped OK, it shot a .37 ctc 10 shot group in light wind with no wind hold. The hole only a little wider than high. That is in the ballpark by me. Then adjusted zero and shot for score (396-29x). Not what I aspire to but what I often get. In the end I shot 80 rounds and not one bad one.

I will continue to pay a little more attention to the carbon ring until I can look at it with a borescope.

I will also change my maintenance in the winter. I think there was corrosion due to condensation caused by the rifle coming in from the cold every day. I wipe down everything with Fluid Film and that has worked well but I can not get inside the bolt. Next winter I'm dropping the bolt in a varsol tray when it comes in the house. Check with me in a year as to how that worked.
 
#25 ·
Thanks everyone.

Took the bolt apart again and polished the striker and the hole it passes through. Same for the firing pin. Even did some light work on the spring itself. After the initial cleaning of the bore I felt that I could see a carbon ring so the barrel got scrubbed, soaked, scrubbed, soaked, etc. In the end I think I still see it but went out and shot it anyway.

After 10 foulers, the last eight of which grouped OK, it shot a .37 ctc 10 shot group in light wind with no wind hold. The hole only a little wider than high. That is in the ballpark by me. Then adjusted zero and shot for score (396-29x). Not what I aspire to but what I often get. In the end I shot 80 rounds and not one bad one.
Glad shooting improved. By doing two different things you didn't prove where the cause of the poor grouping came from. Was it the bolt work or the cleaning or possibly a little of both. I do one thing at a time to verify where the issue was.
 
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