300 WSM & 7 SAUM rate of increased MV??

[DenisA]

I just wanted to finalise this thread as I've sorted out this issue and it might help someone else out one day.

This barrel now has 1250 rounds through it.

The solution was bullet coating. I chose moly as it was easy to access.

I decided to polish the bore back to 100% steel with Autosol verified with the borescope. I moly coated the remaining 185 Jugs that I had. I ladder tested again to find the node at 2910fps which is now 66gn ar2213sc +/-. I polished the barrel again and fine tuned the node for a clean barrel tune.

At the beginning of this experiment, I was very lightly pasting the bore after each days shoot and just running some wet patches through after each detail. That worked really well and has maintained the MV perfectly.

I've recently put 100 rounds through the barrel with nothing more than a light clean at 70 rounds and the MV is still perfectly stable at the low end of the node.

This proves in my mind that coating bullets does help A LOT in reducing the amount of baked ceramic carbon sticking in the barrel. Its also makes it much easier to get a much better result when cleaning barrels without paste.

I haven't needed to pre moly the bore. The first shot after the barrel is scrubbed and/or polished is always a minute low and then it shoots great waterline.

I'm looking forward to starting the next barrel using WS2 from the beginning.

[williada]

Denis,

You may have fixed something that was broken in terms of the steel porosity. Lubricants can fill and smooth and make carbon easier to remove in many cases. When to clean can be a bit perplexing with lubricants. If you can afford the time to run over a chrony more often you may find the change-up in velocity from normal is a good indicator to when to refresh with a thorough clean.

[KHGS]

I just wanted to finalise this thread as I've sorted out this issue and it might help someone else out one day.

This barrel now has 1250 rounds through it.

The solution was bullet coating. I chose moly as it was easy to access.

I decided to polish the bore back to 100% steel with Autosol verified with the borescope. I moly coated the remaining 185 Jugs that I had. I ladder tested again to find the node at 2910fps which is now 66gn ar2213sc +/-. I polished the barrel again and fine tuned the node for a clean barrel tune.

At the beginning of this experiment, I was very lightly pasting the bore after each days shoot and just running some wet patches through after each detail. That worked really well and has maintained the MV perfectly.

I've recently put 100 rounds through the barrel with nothing more than a light clean at 70 rounds and the MV is still perfectly stable at the low end of the node.

This proves in my mind that coating bullets does help A LOT in reducing the amount of baked ceramic carbon sticking in the barrel. Its also makes it much easier to get a much better result when cleaning barrels without paste.

I haven't needed to pre moly the bore. The first shot after the barrel is scrubbed and/or polished is always a minute low and then it shoots great waterline.

I'm looking forward to starting the next barrel using WS2 from the beginning.

Hmmm, just what I have been saying for eons .
Keith H.

[AlanF]

..I'm looking forward to starting the next barrel using WS2 from the beginning.

I have just started using WS-2. Seems to go on and stay on better than the moly I've been using for about 12 years.

[williada]

Hey Keith, and this is discovery learning and its the journey that's important. Its a bit like sex, every generation thinks they discover something new and we old bastards think we invented it too. As we get older we go with what works for us at the time. But its a good feeling to know you were on the right track with your technique.

[KHGS]

Hey Keith, and this is discovery learning and its the journey that's important. Its a bit like sex, every generation thinks they discover something new and we old bastards think we invented it too. As we get older we go with what works for us at the time. But its a good feeling to know you were on the right track with your technique.

David, you are right of course, but I have gone through this carbon thing & how to prevent/make it easy to remove just about every 3 months!! It seems to me that no one listens!!
I remember the bad old days before we "discovered" moly, WST & HBN (all of which work) how much of a problem carbon was & is if not controlled. Once I discovered moly & a correct cleaning regime I have never had a problem since. Moly is not a requirement to control carbon, but it sure makes the task much much easier.
Keith H.

[DenisA]

I can understand the frustration of highly experienced people like yourself and David in situations like this Keith.

The advocates of moly and bullet coating are the minority in the industry and therefore when it comes to fairly green shooters like me that have previously not had issues using naked bullets, or with serious carbon fouling, there's nothing apparently broken to fix so I've never felt a need try bullet coating.

It's not until we have an issue that we start leaning on the archived advice in this forum, trying different suggestions and learning through experience for ourselves. And then we can only try one thing at a time (which takes time to test) to understand which process fixes the problem.

The advice of people like yourself and David doesn't fall on deaf ears (even it feels like that), it just takes people like myself a while to attribute it to an issue. Especially when playing with a barrel, cartridge, powder and bullet combination that few others have string shooting experience with.

Also, if I had of been coating bullets from the start, I may never have had this experience and could have remained oblivious to its benefits. It's good to be able to see what others have said.

Archived advice helping people is exactly the reason I dug this thread up and finished it off and given that it agrees with many other posts that you, David and other people have made, it only serves to reinforce that information.

Thank you Keith and David for all the good advice that you share with us.

[DenisA]

..I'm looking forward to starting the next barrel using WS2 from the beginning.

I have just started using WS-2. Seems to go on and stay on better than the moly I've been using for about 12 years.

Alan another massive benefit I see from moly is that although you have to increase the powder charge to get the same speed, it must result in significantly less chamber pressure or just a kinder pressure curve than naked bullet produce. I've run some fast moly coated loads in .308 recently which I fully expected to loosen primer pockets (as I've seen with .308 LRP lap brass in the past) and found them extremely tight still after a few firings.

Thinking about that makes me reflect on the old .284W Lapua brass threads about primer pockets opening up early and you never seemed to have the issue running as lower MV as myself and others.
You've been moly coating bullets through all that which offers a reasonable explanations for your differing results.

[AlanF]

...Thinking about that makes me reflect on the old .284W Lapua brass threads about primer pockets opening up early and you never seemed to have the issue running as lower MV as myself and others.
You've been moly coating bullets through all that which offers a reasonable explanations for your differing results.

Yes I think there is probably a smoother pressure curve with moly which helps. But it is one of several things I've had in my favour. Others are slow powder (N165), extra case volume (Shehane), and long barrels (up to 34"). I believe all 4 of these factors mean you can run higher velocity for the same maximum pressure (or if you prefer, the same velocity with lower pressure).

[williada]

Thankyou for raising the topic Denis. You make a good point about re-enforcing sound experiences. Do't be afraid to challenge ideas or accepted practice, it keeps people involved. This forum is polite and diverse, that's its strength.

[macguru]

Umm, maybe barrels that 'speed up" like this are a good argument for barrel tuners ? To keep that group nice and circular (and small)
I admit I am a bit intimidated about introducing yet another variable into the tuning process when all evidence points to the fact that the best improvement I can make at the moment is to read the wind (and mirage) better. My 6x47 can shoot 10 shots in the x ring, but usually I cannot....