Good to Bad—Right Now…

[Larry Gibson]

Given your lube and alloy I would really suspect the powder is fouling the barrel. Add a dacron filler on top of your load. If that doesn't work try H4895 with a dacron filler.

Larry Gibson

[BCB]

I am always confused on this Dacron filler…

I understand it is to fit loosely in the case not be tamped down on the powder…

How does one get it into the case without pushing it to the powder in the bottom of the case?...

Should the Dacron fill then entire interior of the case?...

Thanks…BCB

[Oklahoma Rebel]

my first thought was a dirty powder, then I would try your carnauba red, and maybe up your tin to 2-2.5%, how much antimony is in there? and change things one at a time, so you will know what helps and what hurts. but since you have a scope already coming, try that first.after I started shooting cast, I almost never clean my barrels, and they don't lose accuracy, I must have got lucky on the lube,alloy,powder combo. best of luck to you! keep us updated-Travis

[BCB]

I just used QL to predict a charge of H-4895 that would produce the same 1753 fps as the 27.0 grains of Benchmark…

It shows 28.3 gains of H-4895 so that might be worth a try. I have not seen that light of a charge listed in any manual. Although I didn’t find a charge of 27.0 grains of Benchmark either—used QL to get that data…

What is interesting is that when I had QL find powders in burn rates a bit faster and a bit slower than Benchmark, it listed a charge of 27.2 grains of Benchmark to produce 1753 fps. I am using 27.0…

Moving Forward…BCB

[OS OK]

I am always confused on this Dacron filler…

I understand it is to fit loosely in the case not be tamped down on the powder…

How does one get it into the case without pushing it to the powder in the bottom of the case?...

Should the Dacron fill then entire interior of the case?...

Thanks…BCB

In an 87% powder filled 8mm, I use .5 grain of dacron to fill to where the base of the boolit is the last part of the stuffing...pushing the last of it onto the powder. I use a little pencil length 1/4" wooden dowel.
Once you have weighed out what you need to fill your case...pull it apart and separate the dacron as much as possible. You aren't trying to pack the powder in the rear of the case by volume and density...it's more like a cloud of dacron taking up that extra space.

You certainly don't want to use grits or malt-o-meal or some such...it could compact in the neck, jam up, and cause a plug for an instant and cause a pressure spike.

[BCB]

Well, got another 70 sized and lubed with stick Alox…

I put a piece of painters blue tape on the stock of the rifle and am doing the count thing to see when the accuracy might begin to lessen…

I thoroughly cleaned the bore to the point that white patches being pushed through came out almost as white as they entered the bore…

So far I have only fired 15 rounds and the rifling at the crown are as clean, almost, as they were after the cleaning. The lube star on the barrel surrounding the crown/muzzle is about as perfect as I can see with a low powered magnifying glass…

Guess we will see how long it takes for accuracy to lessen. If it is 50 or so rounds, I will accept that and hope that further shooting might allow for that number to increase…

This MGM barrel is good as when it is cleaned the bore and grooves look sharp and as smooth as silk. I realize the eye might not pick up all marks in the barrel, but if I compare it to other barrels I observe, it is “perfect”…

We shall see what we shall see as I continue to put lead downrange…

Thanks…BCB

[BCB]

Almost embarrassed to post this pic!!!...

This is the worst I have seen the muzzle on this rifle…

Accuracy has gone downhill again after 35-40 shots…

Plenty of grey-wash on the rifling/bore, but, is that enough or more than enough to cause radical accuracy changes?...

I suppose I could try Carnauba, but I would need to clean my LAM 2 out as stick Alox is what is in it now…

Any thoughts?

Thanks…BCB

[Toymaker]

Not saying this is it, but this happened to a friend with an Encore and it took us an accident to discover the problem.
Really great accuracy when suddenly its gone. Poof. From sub-MOA to a shotgun pattern. Check the screws, check the mounts, check this, check that, clean the heck out of the barrel. Accuracy's back.....until it's gone again. Cease fire for a relay break, no handling of firearms. Go inside and grab a couple of books trying to find information on the issue. On our phones checking the internet for information. A good hour, maybe an hour and a half, has passed. Back to the bench and shoot a couple of rounds. ACCURACY IS BACK!!!
Accuracy is back, but the point of impact isn't quite where it was before. Keep shooting and watch the barrel temperature, by feel. When it gets hot and the blocks are warm, accuracy goes away. Take it into the range house (A/C) and let it cool. Accuracy returns, but POI is a little different. Shoot slow, keep the barrel from heating up too much and he didn't loose accuracy.

[David2011]

BCB, after reading Toymakers post, have you tried cold bore shots without removing the fouling?

[BCB]

BCB, after reading Toymakers post, have you tried cold bore shots without removing the fouling?

I never have, but I am not so sure the barrel was "hot". That is a very subjective thing. It was about 60 degrees temperature when I was shooting it and I was only firing 4 or 5 shots and not really quick as I have to lift the rifle from the bench to break it open, unload it, load it, position back on the sandbags and then shoot. The reloads are so lightly loaded that I don't even need to apply lube to size them--no hot loads...

The barrel was warm, but not what I would call hot...

Might be worth a try the next time it gets as fouled as it was in the photo posted. I did clean the barrel thoroughly but I haven't fired a round from it yet--Gotta love the Western PA weather...

BCB

[Smk SHoe]

Has the barrel had any jacketed bullets thru it? Could any machine marks from the rifling process be stripping lead off the bullet. I have had barrels that to 100-150 jacketed bullets thru it to settle down. Lead could be a lot more.

[BCB]

Has the barrel had any jacketed bullets thru it? Could any machine marks from the rifling process be stripping lead off the bullet. I have had barrels that to 100-150 jacketed bullets thru it to settle down. Lead could be a lot more.

Nope, no jacketed bullets. I bought the barrel strictly for cast boolits...

Compared to some T/C production barrels this MGM barrel looks as smooth as silk...

Thanks...BCB