6 SLR throat erosion

[Cakes]

Replaced my primary barrel with a new one after 1500 rounds and had a chance to take some measurements of how the barrel throat compared to when it was new. Have no borescope so it is bearing surface to touch measurements. First 900 rounds were a fairly stiff load of H4350 and 107's while the last 600 or so was H1000 and DTAC's. Best I could measure was that the throat has eroded a total of 20 tho. over the course of 1500 rounds. Probably more so with the 4350 than the H1000 as it is quite a bit cooler IMO. Barrel still shot HM scores at 600 but the x-count for whatever reason was starting to go down a bit...probably my age showing!! Any other 6 Super guys that have replaced barrels and measured how the throat progressed. I suspect this new barrel will easily make it to 2000 rounds with the H1000 and I'm not fully retiring the old one yet. Thanks, Eric in DL

 

[tonysnoo]

We set my barrel back some where north of 2500 rounds. Some f class abuse, but mostly steel varmint games. It still shot competitively but we didn't want to lose it mid season.

We didn't measure the wear other than chasing bullet seating depth. I was running .023 longer when we set it back. The casting was a bit rough. We took 1.5" off to feel good about going to the trouble.

 

[chkunz]

Consider having a machinist section the first few inches of the "shot out" barrel so that you can actually look at the area just ahead of the case and see what it looks like. I did this recently and it was informative. The dimensions we are talking about with the lead and rifling are tiny. I think a lot of barrels are removed before they are actually shot out and are blamed for poor shooter performance. I am not saying that is true in your case but just raising the point that it is difficult to know since each match presents it challenges.

 

[Bob3700]

Just a couple of thoughts about setting bbls back.

First off, I don't know if I would do it if I was paying someone to perform the work. It probably cost the same to set it back as it does to chamber a new one.

If you are doing the setting back yourself, that is a different story.

Me, I would not wait until I thought the bbl was "done" before setting it back.
There are dimensional changes that take place on the chamber end of the bbl that aren't going to be fixed by simply setting it back. The negatives on the chamber end are not just throat wear.

Get some gauge pins and check the chamber end of the bore and compare those readings with the muzzle end when you think the barrel is "done". The chamber end gets bigger quicker cause of all the abuse it takes. Pins that just fit the muzzle will drop into the bore on the chamber end no problem. That end of the bbl is obviously larger in diameter. Knocking an inch or so off the chamber end is not going to make the bore smaller.

If I was going to set a bbl back, I would do it at 1/2 life or so. That way, the dimensions in the throat area are less worn and you will see the accuracy maintained longer.

Just one cowboys thoughts.

Bob

 

[JohnMill]

If I was to want an 6SLR to last a long time I sure would take Joe Sr's barrel maintenance regime to heart.You can't argue with the results.

 

[tonysnoo]

If I was to want an 6SLR to last a long time I sure would take Joe Sr's barrel maintenance regime to heart.You can't argue with the results.

What is that? Where has he posted it?

 

[JohnMill]

Understand this was designed for the 6CM. I would go back to Joesr's profile page and search through his postses to try to find it. Joesr is just up the front page with a topic of 6CM testing results.
It is basically using slower than usual powder and every 3-400 rounds polishing the bejeebus out of the throat/barrel with JB. They get 4000 rounds life of barrel. And the technique works just as well on the 6SLR.You'll have to do some legwork to get the info but there are great bits of knowledge along the way.
Oooooor someone on this thread could provide the correct technique etc. etc. etc. (always wanted to say that).

John

 

[JohnMill]

Or just search 6CM and get the whole story.
I like N165 or H1000 for powder and 115coated DTAC bullets for the 6SLR . I turn necks but that is just my way cause I started in PB BR.
Also Nathan Foster, the New Zealand guide and writer covers throat polishing in one of his books.

John

 

[JohnMill]

Or just search 6CM and get the whole story.
I like N165 or H1000 for powder and 115coated DTAC bullets for the 6SLR . I turn necks but that is just my way cause I started in PPC BR.
Also Nathan Foster, the New Zealand guide and writer covers throat polishing in one of his books.

John