FTR rifle problems

[JoeZA]

Good morning everyone,

My barrel was cut with a PTG reamer. It is one of the standard reamer prints for the 185 juggernaut with 0.123 freebore, 1-15 leade and 0.340" neck. The necks are turned and after neck sizing the round measures 0.334". The 185 has a 20 thou jump to the lands.

The rifle shoots great however after 60 or so rounds the rifle starts shooting verticals and after 80 rounds the bolt starts to get sticky and at 90 rounds you really struggle to chamber a round.

Myself and another FTR shooter used the exact same reamer and we seem to be the only ones having this problem?

What are your thoughts on the issue?

 

[lawrence97]

Have you trimmed your cases?
The neck on your cases may be a tad long and causing pressure spikes and feeding issues once the fouling builds up.

You could also have a carbon ring. After the 60-90 rds what does the bullet look like after you chamber a round and then remove it? If the bullet has some scratches that don't look like what you would see if you jam a bullet and then remove it it is carbon build up.

 

[JoeZA]

Cases are trimmed well below the maximum length. I checked the bullet after 60-90 round and there are definately marks on the bullet when chambered. So then carbon build up? Are some powders more prone to carbon build up than others?

 

[BoydAllen]

Yes. some powders are more prone to carbon, and from your description, that is your problem. How do you clean?

 

[lawrence97]

I had the issue pop up on one of my rifles that had always been cleaned with patches until they came out white. After several hundred rounds, my rifle did the same as yours and I noticed it when I was checking for throat wear and I couldn't get the lands to mark the bullet because it would not go all the way in. Bullet would come out as if it had been run through sand paper!

That is when I figured there was carbon and it required a deep clean with brushes and also JB or iosso. I cleaned it as normal with patches, then I put some JB on a patch and wrapped it on a undersized nylon brush and spun it in the throat area a few times. Then I ran patches until they came out clean. From that point on I use JB after every 200-300 rds to keep that carbon out.

 

[Keith Glasscock]

This is the area where I really enjoy my investment in a borescope. I can see the carbon ring, and I can see when I get it all out.

Try finding someone with a borescope and give it a look. You'll be amazed how much is still in there after you think you removed it.

 

[SWRichmond]

I had a similar problem. Agree with checking for powder / carbon fouling in the throat. Use JB to get it out if you have to. I did.

 

[BoydAllen]

In my experience, backed up by a borescope, (carefully used) IOSSO is superior to JB for taking hard carbon out of a barrel. I have and use both products, and like them both, it is just that I have found IOSSO to be superior for this particular task.

 

[Scott Harris]

Have someone with a pin gage check the neck dimension of your chamber. Just because the reamer says .340 don't make it so. Or check your fired brass....should come out around .339

 

[JoeZA]

Checked the fired brass necks last night and all of them are 0,339". Looks like the reamer is fine.

The other thing apart from the reamer that myself and the other shooter have in common is that we often interchange between the 175 LRBT and the juggernaut.

Could shooting different kind of bullets maybe promote the build up of a carbon ring?

 

[mattt]

What is the oal of your loaded 185 jug?

 

[JoeZA]

2,315" to the ogive.

 

[SWRichmond]

Thinking about your "hard chambering" problem, I have another thought to add. I have added an additional step to my cleaning routine in order to specifically clean the chamber area forward of the case neck. A surprising amount of crud builds up here, and I supposed it if built up enough and hardened it could cause jam case necks during chambering, causing accuracy and pressure issues. Pure speculation, but I think factory / SAAMI chambers are deliberately large enough to mitigate this problem, while custom tight neck chambers require extra care.

I, too, fought with a very persistent pressure issue which seemed to build up after cleaning. One additional thing I stopped doing was neck lubing my cases with graphite prior to seating, which I now believe contributed significantly to buildup.

 

[sdnerf]

If you have a chambering problem you can resolve it by drill and tapping a fired piece of brass. Screw a bolt (double nut the bolt to have a stop for the brass) into the end of the brass (6" long should work) this will allow you feel the empty case as it enters the chamber. If it seem clear of obstruction then you can seat a bullet into the case (long) and spin the bullet into the lands to see if you get a clean groove cut into the ogive. If not you have some fowling going on.
regards,

 

[Quickoz]

What powder you using? I'd clean with JB or Iosso at least every 100rds if not less to keep carbon down. I clean my 7mm08AI every 50 rds with Iosso and its squaky clean all the time and shoots awesome. I do the same with 308 and 155gr to keep in top of the carbon. It will hurt your barrel.

Also when patches come out clean, it doesmt mean that your barrel is clean, just means that the patches arnt picking anything up anymore. Boretech Eliminator and Iosso will be your friends.

 

[dkhunt14]

What is the loaded diameter of your necks? It doesn't matter what the sized diameter is, it only matters what it measures after a bullet is seated. Matt

 

[gsg5pk]

What is your ammo COAL for 175 and 185 with this chamber?