Stiff Bolt Part 2. Pics up!!

S

skeetlee

Active member
Fellas
Some of you may have read about some concerns i had with a BAT SV action with a stiff bolt after firing a shot. I was reading the post By Mr Jackie Schmidt were Mr Schmidt had to lap his bolt because it was simply to tight in the race way. After reading that post i started to wonder what the reason, or reasons were that my bolt was so darn stiff after firing a modest load of N133 in my 6ppc rifle. My load is 28.8gr and there are no signs of pressure on the brass. I had also stated that the barrel i am shooting was purchased as a take off barrel and that it might be rubbing against the bolt cone. That definitely isn't the issue as i have check it thoroughly. Well i think i finally may have an answer as to why i am experiencing the stiff bolt.
Here is what i am thinking after some investigation, and i would like for someone to possible confirm, or otherwise to this situation. In the picture i will post below you will see several uniform lines on my brass that go all the way around the case in the exact same spots from brass to brass. You can even feel them with your fingernail by running your nail across the circles or lines. I am thinking my chamber is a bit more rough than it should be. and i am also thinking this might have something to do with the stiff bolt problem. The rifle is shooting just fine, and i even won the local varmint for score match today with it, only dropping 2 points all day. The rifle seems to group ok as well. I did clean a lot of carbon out of the bore last night but i dont think that has anything to do with anything. Anyway here are a couple pieces of brass and you can see the lines i am speaking of. Please explain to me what you see, and it possible effects. I guess the only real down side to this, is that my bolt is so stiff, it moves my rifle around in my bags to darn much, and i am spending way to darn much time getting back on target. Other than that i think i can live with it, but if there is an inexpensive fix please explain. Fellas, I always appreciate your help and conversation!!
Hope everyone got to shoot today, and i also hope you all shot well. I had another pretty good shoot today, and i feel Like i am progressing just fine, thanks to you good people. Thanks again! Lee

ppcbrassrings001.jpg
 
Skeet

Those rings are not normal, whoever chambered the barrel either let the reamer clog up with shavings, or the reamer needs a good stoning, as it could have minute particles "welded" to the cutting edges.

But, that will not cause a bolt to open hard from the very beginning, What that will do is cause a very severe "click" at the very top of the stroke as the bolt handle reaches the primary extraction point. Why?? Those tiny grooves you feel actually fill in the grooves in the chamber.

Have you tried a barrel that does not produce cases with the grooves??......jackie
 
I am waiting on some new turned brass to come home, and i will try the second barrel i bought. I have a feeling they were chambered with the same reamer, as i purchased the 2 barrels from the same gentlemen. I did notice a few cases clicking today, but i figured that was because i used a number 1 harrells fl size die and not the number 2.5 i had been using. I guess that doesnt really matter though, as the cases blow out after the shot anyway. The rifle shoots pretty good, i just wished it opened up a little easier, and i dont know for the life of me why. I hate to have to put another 200 bucks into this action, but i may have to i guess. I will have as much in this little SV as i would a new 3 lug or a model B, if i have to send it off. That sucks!! Lee
 
If those grooves on the brass are only a tenth (0.0001") or so deep, the chamber is probably not the problem. If they are a few tenths deep (say 0.0003" or so) deep they would at least be a contributing factor to your problem.

If you don't have access to a bore scope, put a good light at the muzzle and take a magnifying glass, you may be able to see the marks. If both barrels look alike, send them back. Some reamers shipped today are either not carefully ground or not stoned after grinding. That is the difference between a good reamer and a great reamer.

A few weeks ago bought a new, unused, 6BR reamer at a recently deceased gunsmiths estate sale that reams chambers that look just like that. That reamer was from a top reamer grinder and no it was not Hugh Henriksen!! His reamers are carefully stoned after grinding.
 
Bummer!

Lee, you have two problems,, Jackie Schmidt described them perfectly.

Such a rifle may shoot very well but you will always have difficulty opening the bolt until the barrel is set back and the chamber recut to remove the concentric rings and the bolt body lapped or polished to relieve the binding. The bolt binding is understandable and happens quite often with this action and is no big deal but there is no excuse for the bad chamber. One who would let such a chamber out of his shop is not someone I would trust to correct it. Take the rifle to a reputable benchrest gunsmith that knows what he is doing and has good reamers that do not produce ringed chambers.

Gene Beggs
 
let me make one thing clear before we go any further. I didnt pay anyone to cut this chamber for me. I bought this barrel as a take off, and for a very fair price. the barrel wasnt ever chambered for the intended purpose of resale. The shooter/ smith that this belong to,, cut the chamber for himself and the barrel must not have shot up to his standards. So i can not complain about that even in the least. Nor would i want to. What i would like to know is if this is the, or if this could be, the reason for the bolt stiffness? To be real honest i have cycled this brass through this barrel about 4 times now and i didnt even really notice the rings until last night while reloading for today's match.
I guess i was hoping someone was going to say that this is the problem and that my action doesnt need a thing, but i am not that lucky, on most days. When my new turned brass gets back, i will screw the other barrel on and see what happens. After i said that the barrels will probably be the same in the above post, i stopped and remembered that when i was checking headspace right after i got both of these barrels the other barrel is .005 shorter so maybe it will be a different reamer, although i do realise that that doesnt necessarily mean anything either. I will just have to see i guess.
Of course i would like for my bolt to be a bit smoother, as the darn rifle is shooting pretty good. This is my back up rifle, or my club level rifle, so it isnt going to be the end of the world if i have to send it off, but i hate like heck to have to spend any more money on the darn thing. thats the kicker for me. I have sold all my odd ball stuff to go with only BAT action and i hope this isnt going to be an issue with the other two rifles that are about finished. i like being a positive type of person though, and i am keeping my fingers crossed that the barrel is the problem. I will post as soon as i know. Thanks Fellas, i enjoy your company. Lee
 
.005 Difference

If these barrels were done by the same Gunsmith, at the sametime, that should raise a red flag as to capabilities. When dealing with a Benchrest Rifle, that is WAY too much variation in the headspace.

It makes no difference what reamer is used, the headspace measurement is taken independent of the reamer.

Skeet, another thing. There is a big difference between bolt "stiffness" and hard extraction. Stiffness means that the bolt is difficult to lift from the very start. The culprit in this can vary. Too hot a load for the combination is the biggest factor. Problems such as I encountered with my Rifle are another. This type of stiffness is a result of the brass not shrinking back enough after each firing.

Difficult extraction means that the case is stuck in the chamber,either because the web area is too large for the reamer, the cases are simply past theirusablelife for the equipment being used, (dies), or the "rings" that are present in your chamber are actully forming a positive grip on the case walls.

Exactly which are you experiencing...........jackie
 
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First off i apologise for not being very darn good with words. I am terrible at anything grammar. I wasnt much of a student back in the school days, my mind was wondering if the dove fields were hot that afternoon or if the walleye were up in the river yet.
Here is the best i know how to describe the situation. The bolt feels like there is to much pressure after firing the shot. It is hard to open from the very start. It isnt extremely hard, but enough that i know it isnt correct and enough that it moves my rifle way to much in the bags. The brass doesnt show any signs of over pressure, so i am not going to say that isnt it, but it doesnt appear as so. I will say that at 27gr of N133 the bolt felt better, at least i think. I only shot a couple rounds with that low of powder charge, but i seem to remember it feeling a bit better. I would also like to add that when i chamber a piece of fired brass, it is very difficult to close the bolt. We were messing around with that yesterday. We took a couple pieces of brass that i had just shot and stuck them back into the chamber and it felt really tight. Is that normal?? My loaded rounds chamber just fine, so i know i am properly bumping my shoulders back. The brass was new to this chamber, but i cant say for sure it was turned properly. I dont have the tools to check. The other barrel also has the same tool marks as i can see them with the barrel being off the action. I dont want this to turn into a bashing thing for the person that chambered these barrels, as he is a good man, and well respected. I knew full hand i was buying a used, as is barrel, and i would like to purchase more of them in the future as they are shooting just fine. I would just simply like to know why i have such a stiff , over pressure feeling bolt. I would think at 28.8gr of N133, 08 lot, it should be fine, and if it cant Handel that, it probably isnt much use to me. At least thats the way i understand it? I suppose i could take my bruno ppc BAT barrel and screw it onto this action and shoot it, but to be honest i dont want to touch the darn thing as it is a hummer barrel and i dont want to take any chances until after this years shooting is done. I guess I can live with this action for now, but i really would like to know whats going on with it. Maybe some one at the East west shoot can take a look and help me out while i am down in St Louis. I will, in the mean time try some 8208 and some other lower charges of N133 to see if it is in fact pressure. Like i said, myself and several other competent shooters see no signs of pressure on these pieces of brass, but i am pretty new and maybe i just dont know what to look for?? One thing i am wondering as i type this, is if that brass should be hard to rechamber after firing it. there is no way i could just neck size this brass ( not that i would) and re shoot it. Is that a normal occurrence? thanks and please lets not make a big deal about the chambers, as thats not what this is about. I purchased these as is, and i even had a chance to shoot them before i purchased them, but i chose not to. If thats the problem then thats all i need to know. I just wish i had another barrel to try. Maybe my shooting partner will have one i can screw on. We will figure all this out one way or another. Thanks for all the help! Lee
 
I have gotten similar marks on the brass with a Harrels die.. When using other dies on the same brass, on the same chamber, I didn´t get the marks. Go figure.

I have always had problems closing the bolt on fired brass, but thats with a whole lot harder loads than you are using. You can close it, but then you have to out in some presure on the handle.

28.8 is quite a soft load, so it´s quite strange that you are having truble. You probably have the same issue as Jackie had.
 
P.Ericson said:
I have gotten similar marks on the brass with a Harrels die.. When using other dies on the same brass, on the same chamber, I didn´t get the marks. Go figure.

I have always had problems closing the bolt on fired brass, but thats with a whole lot harder loads than you are using. You can close it, but then you have to out in some presure on the handle.

28.8 is quite a soft load, so it´s quite strange that you are having truble. You probably have the same issue as Jackie had.
Click to expand...

I doubt if a die would cause those rings. The Harrells may show them up worse if the Harrells is bringing the brass down further than a die that doesn't show the rings.
 
The die is fine. Does the new 8208 operate at the same pressure as N133? Maybe i can work up a load with 8208? We have the new 8208 as well as some of the old 8208. Please advise. Thanks Lee
 
Ken Worth said:
I doubt if a die would cause those rings. The Harrells may show them up worse if the Harrells is bringing the brass down further than a die that doesn't show the rings.
Click to expand...

The other dies I`m using hit the case more than the Harrels die. Have never had the problem with other dies, but when I first ran a case thru a harrel die I thoght -"what a heck is this?" The marks vanished after some use, so I guess it was some ruff spots in the die.
 
I recently had a 6 BR live varmint rifle refitted and rechambered because the original work was crap. That's being kind too. Apparently the chips weren't cleaned from the reamer often enough or properly or the reamer was dull.

The second smith said that there was a groove in the chamber where the body and shoulder met. Bolt lift was stiff with any load, extraction was difficult, and the fired cases needed to be sized in a small base die so that they'd chamber properly too. I measured some of the fired cases and the chamber wasn't oval either. The new chamber is the way a chamber should be, no small base sizing required, and bolt lift is what I'd consider good.

The marks on your cases aren't normal in my experience. If Jackie says something is wrong I'd put my money on him, he's likely forgotten more about good machine shop practice than most of us will ever know.
 
The marks on your cases aren't normal in my experience. If Jackie says something is wrong I'd put my money on him, he's likely forgotten more about good machine shop practice than most of us will ever know.


I wouldnt question that for a minute!! Jackie has always been a good source of truthful information, and i enjoy reading what he has to say, along with several others here. this is a great site!!! Lee
 
Ken Worth said:
I doubt if a die would cause those rings. The Harrells may show them up worse if the Harrells is bringing the brass down further than a die that doesn't show the rings.
Click to expand...

What you are seeing here is a condition called BUE (built up edge) by the reamer. BUE can be caused by several factors, dull cutting edge, SFM (speed) too slow, lack of or improper coolant.

http://www.gosteelgo.com/articles/Types-of-Chip-Formation-During.htm

There is no way a sizing die can cause circular rings since it does not rotate. If the die is scratched or galled it would leave linear scratches. In any case the chamber is substandard.
 
If they come out of the chamber looking like that, its most likely the chamber. If they come out normal from the chamber, but looked screewed up after sizing, its most likely the die.:)
 
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I wish it were the die! I can see the rings in the chamber. I am not really all that concerned about it really as i have very little money in these two barrels and they shoot pretty good. Just learning barrels for me. I am going to shoot the heck out of them, and enjoy myself. I just wish i knew if that was the reason for the stiff bolt?? Lee
 
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