Question on bullet jump

[Jr Rigsby]

Does jumping a bullet .040"-.050" from jam have any determinable or premature effect on chamber throat erosion. Barrel will be a premium SS chambered in 6mm used in short range benchrest . Any adverse effects on barrel in general. Any thoughts will be appreciated.

 

[dkhunt14]

I don't think it does but they usually don't shoot good there. Matt

 

[Joe Salt]

Listen to you I been jumping them for years and they shoot better than in the lands for me!

Joe Salt

 

[strut64]

Depends on the bullet. Go read Berger's tech notes. tangent versus secant ogive.

 

[dkhunt14]

Listen to you I been jumping them for years and they shoot better than in the lands for me!

Joe Salt

So that's why you aren't winning any aggregates? Never had a gun shoot better off then in. It didn't matter what bullet including Sierra. Matt

 

[lpreddick]

Throat erosion is primarily due to heat/pressure. Bullets , by themselves, cause very little erosion to the bore. Borescope the throat of a .243 that has 1500 rounds, then borescope 6 inches from the muzzel.

 

[Shynloco]

Depends on the bullet. Go read Berger's tech notes. tangent versus secant ogive.

Well, I've found it depends on both the chamber and the bullet. Most of my rifles perform best with the bullet just touching the lands while with a few others, if I get anywhere near the lands, the results looks like a shotgun was used on the target at 100 yards. My point is simply that the chamber and the bullet will tell you what she likes and hates.

Alex

 

[noload]

have any determinable or premature effect on chamber throat erosion???
Thats a tough question for me to answer. My 6mm bullets just touch the lands, and I can get about 2000 good shots down the tube before it goes south. If you jump them and get 3000 good shots, then may be(?) we will know... Problem is.. many things can factor into erosion... speed at which you shoot, powder type, barrel diameter, etc.

 

[Joe Salt]

So that's why you aren't winning any aggregates?

Well Matt I was testing bullets for someone, but I did manage 10th place in ten match for score! H.G.
I know with the 30 cal. I haven't seen anymore erosion or fire cracking!
I use H-4350 and I use a bore scope when cleaning and I can say I haven't seen anything different.

Joe Salt

 

[Jr Rigsby]

The reason I ask this question is that altough, I've not been shooting bench rest but a few years, when I first started I had a barrel that shot great, actually won a lot of wood with it. Loaded approx .010" off jam with 28.5gr LT32, barrel after 1400 rds had aprox.060" throat erosion and did not shoot well. Another barrel loaded with 30.0gr LT32 and approx .002" off jam lasted well over 2400rds and shot just as well as the other did and had very less erosion. Just trying to learn a something.
Thanks JR

 

[ttfreestyle]

I do think master yoda can win wood with any barrel . Wind talker he is!

 

[dkhunt14]

The reason I ask this question is that altough, I've not been shooting bench rest but a few years, when I first started I had a barrel that shot great, actually won a lot of wood with it. Loaded approx .010" off jam with 28.5gr LT32, barrel after 1400 rds had aprox.060" throat erosion and did not shoot well. Another barrel loaded with 30.0gr LT32 and approx .002" off jam lasted well over 2400rds and shot just as well as the other did and had very less erosion. Just trying to learn a something.
Thanks JR

That is just the difference in barrels. I have seen different brands last longer then others. I also believe it depends upon the steel in the barrel. I have had barrels last and some didnt, even from the same maker. I would also think the way it is shot, more shots faster. The burning rate of the lot of powder and the amount of powder have a lot to do with it. Matt

 

[dragman]

I have developed loads for Hundreds of guns over the last few years. I can tell you all but 1 gun I ended up shooting on or in the lands. the 1 that was different ended up shooting at .020 off. Not saying I they don't shoot well off but all of the guns that I could classify as REAL shooters and something I could win with were up on or in..

 

[dragman]

That is just the difference in barrels. I have seen different brands last longer then others. I also believe it depends upon the steel in the barrel. I have had barrels last and some didnt, even from the same maker. I would also think the way it is shot, more shots faster. The burning rate of the lot of powder and the amount of powder have a lot to do with it. Matt

Completely right!
I had a 6.5X284 that I destroyed in less than 700 rounds
I have had a 300WSM that wouldn't stop shooting no matter how bad it looked!