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It could be mixed brass. I would sort by headstamp.
Are the unfired bullets pulling themselves out of the case during recoil?
I would measure six rounds and load them in the gun. Shoot two then measure the remaining four and see if they have lengthened. Seating depth affects pressure and if the bullets are pulling out, the pressure will drop causing a loss of velocity.
These look to be Speer Gold Dots. I’ve shot them with faster powders, H322, N133, etc
Never tried TAC with the 62 Gold Dot, but I have shot the 62 Hornady BTHP with 25.1 grains of TAC. My notes show sub MOA groups out of my 1:7 twist bolt action.
If you are worried about a pressure spike, I would lower the powder charge by 0.2 grains and use that as a starting point.
No reason to get grumpy. In case you didn’t realize, this is a public forum. I am not an employee of RMR.
If you cannot find what you want from RMR, there are still several manufacturers that make bullets here in the US.
Bullseye is a fairly fast burning powder powder to use in 9mm. No need to run a magnum primer but it will work.
I would follow 124 grain recipes in the Alliant manual. You will probably end up somewhere north of 4 grains.
HKs have tight springs out of the box. Your loads need to be on the warm side to make them run.
You need to do the “plunk” test. Some barrels have tighter chambers than others.
Take the barrel out of the pistol that you want to test. Hold the barrel, muzzle down, in your hand. Drop a loaded round into the barrel chamber then remove it. Does the loaded round come back out freely or stick a little? If it sticks, you probably need to seat the bullet deeper.
To be clear, I am not saying to use a threadlocker on the barrel nut threads. Use a dab of grease for that.
The issue is if there is a small gap between upper receiver and the barrel extension. This will allow the barrel to move around inside the receiver. Adding a small amount of Loctite 602 or similar, to the outside of the extension, then putting it into the receiver, will act as a bedding compound. When it sets, the Loctite will harden, holding the barrel in place.
Similar to putting two pieces of pvc pipe together. You apply glue to the inside of the coupling and the outside of the pipe, then press them together.
50 yards? At 50 yards, a varying 15 mph left or right wind can move the 124 grain bullet about an inch. A head or tailwind is not going to do much.
My experience is that the more I pay for a barrel, the better they shoot. You could try and troubleshoot your current barrel or move on to something with a good reputation. A really good bore cleaner is where I would start. I like foaming Wipe Out or Birchwood Casey bore cleaner. Let them soak to do their thing. When the patches stop coming out blue, you should be good to go.
Another thing is to check the fit between the barrel and upper receiver. Remove the barrel from the upper, then check to see if there is play between the upper and the barrel extension. I have used a thin amount of JB Weld , some like Loctite 620, on the extension and re-torqued the barrel nut. Let it sit a day or two before shooting.
Are you using a suppressor or a muzzle device, etc?
“Winchester FMJ 147 Gr gave a 1/2″ group with a 1″ flier”
Does this mean two shots were close together and one was further out?
I would use more than 3 shots to determine group size if you are going to consider flyers. Your sample size is just two small to get a conclusion. I shoot two 5 shot groups, allowing the barrel to cool in between.
Make sure your powder drops are consistent. Neck tension is also something that affects groups.
One thing at a time though. Shoot some factory loads with the bipod and use that as a baseline. Next try swapping primers and make sure the power charge is within .1 or .2 grains.
Make sure your powder drops are consistent. Neck tension is also something that affects groups.
One thing at a time though. Shoot some factory loads with the bipod and use that as a baseline. Next try swapping primers and making sure the power charge is within .1 or .2 grains.
A change in primers may help but I doubt it will shrink groups by half.
Have you measured velocities with a chronograph?
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