Does a longer bullet cause faster throat wear?

[RossL]

A friend told me that the longest bullets in 6mm, like the 115 DTAC or Berger 115 VLD are the worst offenders in wearing out a barrel's throat. If I wanted to extend the barrel life on a upcoming 6mm-284 would I be better served shooting 105s, and 107s vs 115s?

I understand there are many variables involved. Many of us could make all sorts of theories as to whether this is true or not. I would like to hear from anyone who can comment based on their experiences with their 6mms.

thanks,
Ross

 

[Steve Blair]

Re: Will a longer bullet wear out a bore faster than a shorter one?

The throat goes first. I do not think that frictional wear is an issue. It may be that the longer heat exposure each shot because of slower bullet acceleration could contribute to faster failure.

 

[RossL]

Re: Will a longer bullet wear out a bore faster than a shorter one?

It is theory. I was hoping someone would come along and say Yes I experienced that....or didn't.

I cannot say what my friend said is factual. I have my doubts but no experience to prove it. Like most handloaders I try all sorts of bullets and eventually settle down to shoot THE bullet. I have not worn out many barrels but I'll bet there are some BR guys that have. I also believe that some of the guys in the know wore out a barrel in a 6mm before longer bullets were created.

I'll throw these two out...faster twist barrels are needed for the longer bullets..perhaps THAT is the issue and not the bullet. On the other side of the arguement there is less powder used with a heavier/longer bullet and slower velocites which should prolong barrel life. BUT I am theorizing........

 

[Scott Harris]

Re: Will a longer bullet wear out a bore faster than a shorter one?

You want to extend the barrel life on your 6-284? LOL, now that's funny. You've chosen the wrong caliber if you are worried about barrel life.

 

[Steve Blair]

Re: Will a longer bullet wear out a bore faster than a shorter one?

I have fried a number of 6mm Remington and .22-250 barrels and the barrel past the throat still looks pretty good when the throat looks ready to shed some pieces. That is determined using a borescope.

Scotharr is right. Long bullets or short, you will not get much barrel life from a 6-284. 6mm Rems have given me 800-1200 rounds with sporter to medium-weight varmint barrels.

 

[RossL]

Re: Will a longer bullet wear out a bore faster than a shorter one?

Scothar,

I am not worried about barrel life. I know what I will be building. The 6mm-284 won't be used for competition. Long range varminting for glassed up jackrabbits and the occasional coyote. Single shots are the norm as the animals don't hang around after the shot. It is the best simulation of coues wt hunting I know, which is the reason for this activity.

I am no tyro in regards to shooting rifles and handloading been doing it for over 25 yrs.

I had a legitimate question which has not been answered.

I changed the title of the thread to "Does a longer bullet cause faster throat wear"

 

[bozo699]

RossL,
There are many things that come into play when talking throat erosion and barrel wear, and there are many different theories. I have read many different things about it but these are my thoughts on it, mind you there just my thoughts. The longer the bullet the more bearing surface you will have which will create more friction going down the barrel wich will give the riflings more wear and tear in the long run than the shorter bullet even though it is going faster. Boat tail bullets are said to cause more throat erosion and if you think about it I believe they do. Shorter bullets are faster and have more powder behind them but my barrel is always hotter to the touch when shooting long bullets than when shooting shorter bullets for the same amount of shots, for whatever this is worth to you there just my opinions. Oh by the way welcome to the forum.
Wayne.

 

[fdshuster]

To me, a question like this is hard to prove one way or the other, but I can relate my experiences with 2 different 6BR chamberings. The first is a heavy contour stainless Shilen, 1-14, .265" chamber neck. Fed an exclusive diet of 30 grs. of N133, 68 gr. Berger #24411 seated to touch, all firing single shot and slow. At a recorded 1525 rds. fired, and as seen with my Hawkeye borescope, there is no sign of firecracking in the throat and bullet seating depth is within .020" of the dimension when new. The second barrel is a heavy contour stainless Hart 1-8, .272" chamber neck. Fed an exclusive diet of 30 to 31.5 grs. of Varget, 95 gr. Sierra & bergers, (31.5 grs.), and 105 gr. Sierra's with 30 grs. of Varget. All bullets seated to touch and single shot, slow. In the area of 1500 rds. fired saw the beginning of firecracking, a little more copper fouling, and bullets had to be seated further and further out of the neck to keep touching. Then started to get uncalled flyers to the point the barrel could not be trusted in a match. Now, at 2000 rds. the barrel has been pulled off the receiver, and a new chambering is in the shop. When a faster twist and heavier bullets are needed for the longer distances, that's the price you pay.

 

[RossL]

Thanks for the welcome Wayne.

fdshuster: your experience is what I was looking for. Thanks

 

[KevinThomas]

RossL,
Frank and Steve are giving you good information here, and I agree completely with Steve's comments about dwell time beign the bug-a-boo here. It takes a tad longer to get those heavy bullets moving down the barrel, and while that's happening, those hot gasses and building pressures are doing their dirtywork to the throat. I've shot out literally scores of 6mm BRs over the years, and there's always been a significant difference in the barrel life of those shot with lighter bullets, and those used with 105s, 107,s and certainly 115s. Frankly, I don't think you'll see much improvement by dropping down to the 107s from the 115s, but there may be some, however slight.

As a personal observation, you pick the bullet based on the job at hand, and the barrel life you get is simply a result of that choice.