BLR in 308 sticking with factory loads.

[M. M. Wright]

This same problem was posed by Hawkins a year or two ago but I bought the rifle and sure enough it requires that you wait about 1 or 2 minutes before the action will open when fired with factory ammo. Remington 150 grain. When they finally come out the primer shows evidence of over pressure loads. The primer has flowed out to fill the chamfer around the pocket and metal has flowed back into the firing pin hole around the firing pin. Sure signs of a "hot load" in my book. I slugged the bore and it is exactly .308, as it should be. No tight spots or loose spots. I tried to cast the chamber with cerrosafe but the casting would not come out with a 1/4" brass rod down the barrel and a big ball peen hammer used on it so I melted the cerrosafe out.
I looked at the chamber with my bore scope and I also used 3 others (all Belgian) to compare what they looked like. Guess I should have taken pictures to show you but didn't. The only thing I saw was some brass stuck to the face of the neck end on the culprit chamber. I guess it is possible for the neck to be so tight that it will not release the bullet without running pressures up drastically.
The same loads that I have tried in this gun give no trouble at all in the BLR which I use frequently. I did try some very light, below starting loads in the Hogdon manual and got away from the flattened primers but extraction was still not satisfactory. I believe the chamber is bulged but what could possibly be wrong that causes high pressure signals with otherwise normal loads.
Could the neck area be too short? Cases have been trimmed to 2.009.
Accuracy is good even with the reduced loads that I cranked out to try it with. Probably have to rebarrel it to fix the bulged chamber anyway but why is it doing this? The only barrels available are "made in Japan" and I find it repugnant to screw one of these onto a "made in Belgium" gun.

[Les Staley]

My first BLR was a Belgium made 308 that was so tight that most factory ammo would stick while trying to chamber it. I made the BIG mistake of disassembling ..pulling the bolt..thought I might be able to ream the chamber (had the finish reamer)...never did get it any better and learned a hard lesson on BLR timing...got it back together and traded it with some boot for the Jap 358 I have now. The Miruko rifle has been perfect..eats anything..shoots like a Browning should..hate to sell it but have my eye on a Ruger Hawkeye in the same caliber..besides, my Savage 99 in 358 will hold me over till I get the new gun...

[BenT]

I have had Brownings with tight chambers. Meaning that when resizing brass if the shoulder wasn't pushed back all the way the round would not chamber. Not sure if that would give the problem you are experiencing. Carbon build up in the throat will give you sticky extraction. Best thing to try is using a finish reamer to clean it out . Of course that would require you to take out the bolt, which isn't a basic job.

I also had a 30-06 Browning with a short chamber. If I used 180gr round nose bullets. The bullet would jam in to the rifling so much that I could not remove a loaded round. Good Luck!

[earlmck]

I guess it is possible for the neck to be so tight that it will not release the bullet without running pressures up drastically.

I can tell you (personal experience )that a too tight or too long neck is a great way to have pressures head toward the moon. If this is the cause, then a new bullet will require some push to go into the neck of the newly fired round. But if a bullet will go easily with some room to spare back into the neck of the fired case then it is something else.

[M. M. Wright]

Thanks Earl, I hadn't thought of pushing a bullet into the case to see if the neck is loose enough. I'll try it. Maybe I'll rent the finish reamer and be sure the neck is long enough too as I can't figure a way to check it without removing the barrel.

[Hawkins]

I can add a little background, since I was the previous owner of this curiosity. The biggest clue I can give is that it seems like the problem is getting worse over time.

I bought the rifle about 20 years ago, from a friend who reported no problems with it. And I don't recall any problems at first, either with factory loads or mid-range handloads. Over the years, I probably shot it a few hundred rounds, again all with factory or very reasonable reloads. As time went by, I started noticing that extraction was becoming difficult. At first it was just a slight resistance to the lever opening as easily as it should after firing, then it gradually got worse to the point where I would either have to take it down off my shoulder and give the lever a hard pull immediately after firing, or wait a few seconds and then it would open almost normally. My mid-range reloads were the easiest to open, 150 grain Winchester factory rounds were more difficult, and 180 grain Winchesters were the hardest to open.

I took the rifle to a Browning authorized repair shop, who said they adjusted the timing of the bolt gears--but it didn't make any difference, good or bad. I also sent a couple of the 180 grain Winchesters back to Olin, and they said they were within specs. It was at that point I gave up and sold it to M. M. Wright, with full disclosure of course.

It sounds like it is now even worse than it was. I do not remember the primers flattening or flowing with the loads I was shooting, or any similar signs of high pressure. And I didn't have to wait for as long to open the lever as M.M. is reporting. My best guess at the time was that the chamber was somehow out of spec, and when the brass expanded upon firing, it temporarily locked the lever in place, until the brass cooled and shrank slightly. However, the pressure signs M.M. has seen make it sounds like something different.

Note that I NEVER had a problem with any rounds chambering before firing, so the chamber was not so tight or undersized as to cause a problem there. My reloads were always full length resized, but not with a small base die.

So, can anyone think of a problem that would cause increased pressures, and that would get worse as time went by?

Hawkins

[M. M. Wright]

Thanks Hawkins, That's the way I remember you telling me it acted at the time I bought it from you. I am sure that a new barrel will fix it so that's probably what I'll do. Don't want to have one gun requiring it's own low pressure loads. I will try another, partial chamber cast with the Cerrosafe. Then maybe try to ream just the neck a little deeper. I want to check the amount of freebore too.

[Hawkins]

Sorry you haven't been able to find an easier fix for it. I was hoping it was something fairly simple and cheap, but not so obvious as to make me feel like a complete dummy for not seeing it

Hawkins

[Old Savage]

I have a 243 that was producing over pressure with factory rounds initially. Talked to a gunsmith that said they sometimes don't get all the polishing compound cleaned out of the chamber mouth. He told me to put some tooth paste on a brush with a patch wound around it and rotate it in the chamber throat an mouth to remove anything that might be there. This solved the issue and the rest of the same box that produced the high pressure signs produced normal pressures. It has been fine since firing many hundreds of rounds.

[jjames]

I had a similar problem with my 308 BLR circa 1978 or so. Went back to Browning 2 times and they said nothing was wrong and they would charge me if I returned it again. They insisted I must be shooting hot reloads which was not the case. Several years later I complain about it to the right person at a gun store and he sent it back to Browning. Came back without the problem and with no explanation. Mine would lock up so tightly letting it cool would not help. I had to knock it out with a rod from the muzzle. Sold the rifle. Have had no similar issue with my 2006 Shotshow Special 308 BLR even shooting Shooter loads than the factory stuff that stuck in my original.

[Sixgun]

Mmmmmmmm....interesting MM.

Take a fired case and a FL resized case and coat them with a black magic marker and chamber them. See if they are getting identical markings. Also, get a micrometer and measure the OD of a fired case (neck)a fl resized case, (neck) and the measurements of the neck of a LOADED round.

Do the same (magic marker) with a properly trimmed case, but blacken up the edge of the case mouth and see if that is getting buggered up.

Take another case and trim off say.....020 ...load it and shoot it....take notes.

Black magic marker the bullet of a loaded round, chamber that, extract and take notes

I know this may be stupid, but measure the bullets themselves. .311's have been known to slip in.

Do what Earl says. That's really the same as above but a bit more scientific with a micrometer.


There is a reason why the pressures are skyrocketing and it should not be too difficult to find out why

It's just a process of elimination. If you know the cartridge is ok, then it's the neck or the bore diameter-------6

[flatnose]

sixgun just saved me from retyping my disappeared post.
Fire the inked up cartridge, and try to extract it as soon as possible, using a bit of force as needed. You should see marks or abrasions on the fired case if the chamber is damaged. Check the bullet tip and make sure it is not touching the rifling (lands), that alone will cause high pressure.

[flatnose]

Another possibility....chambers on leveractions are difficult to clean without taking the action apart and going in from the chamber end. If you have seen brass deposits on the chamber neck, this would account for all your problems. Plug the breech end and fill the chamber with copper solvent....or an outers foul out works good if you have access to one.
Reloaded ammo may have been part of the problem. If you trim the brass before reloading, the outside of the case neck may have not been deburred enough, leaving an excess to be hammered into the chamber neck. It will build up more on subsequent firings causing harder extraction and more pressure each time. A few thousands build up of brass or crud in this area is all it may take to create your rifles symptoms.