Lessons learned on a PSA SS 16inch upper

[TrickyNicky]

I can't imagine being satisfied with 4" groups from any rifle. :shake: I have a cut down Spanish mauser that'll beat that, and I only have $30 in the gun!

4" groups would "satisfy" my PDW needs ok I guess, like you though I would be mighty disappointed if that was the best the rifle can do. I want any limitations for a rifle to rest where they belong, the shooter. I can handle a 4" group on my Nagant at 100 yards, bigger than 4" in fact. My being able to except that is based on the fact that its MY shooting opening up the groups, not the rifle.

[jcluff]

Well, I have removed the handguard and verified that the gas tube is on correctly to the best of my knowledge. I have validated that the hand guard doesn't touch the barrel and that there is a decent amount of space, about .5cm between the guard and the gas block.

I am thinking I need to take the gun to a gunsmith, maybe guns for America, and have them inspect it and see what might be causing it to walk so much when heating up.


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[trevorst]

I still dont think really anything is wrong with this upper, it is quite possible that it isnt properly broken in.  It is also quite possible that you still havent found its sweet spot on bullet/powder/oal.  Most likely it is a combination of all of the above.  Couple all of this with frustration and 3-4" groups are easy, add in a 5.5lb trigger pull when you are going for precision and they are not only easy but expected.

 

Barrel break in is a real thing and is very important for a long lasting accurate rifle.

 

Go to this website, read it... live it... love it.

 

http://www.kriegerbarrels.com/Break_In__Cleaning-c1246-wp2558.htm

 

 

Good luck on achieving one hole goodness, and most of all enjoy it.  A bad day at the range fighting wind and 4" groups is better than work lol.

[RWF]

well?

[jcluff]

I am heading to the range tomorrow and going to do some shooting to collect data on how quickly it starts walking.

I have not heard back from PSA yet. I need call them. I will keep ya posted and provide some pics of my groupings.
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[Dolomite_supafly]

4" groups with Tula are great groups. I have guns that are consistent 1/2 MOA shooters that will not get 4" with Tula.
 
Finding the sweet spot for reloads takes time. You even said you haven't started on load development and I agree that is likely the problem more so than the gun.

I use a chronograph to load. There is a correlation, I believe, Standard Deviation and vertical stringing when shooting at longer distances.

Everyone has their own routine for accuracy testing. I do it this way to minimize my time at the range. I can shoot at my house so I can determine SD's without being at a range. With my testing all components are as close to being identical as humanly possible. Cases the same, bullets the same, primers the same and all are loaded in the same setting. The only variable when I test will be the powder charge and overall length of the bullet.

This is how I test loads for accuracy. I will load 3 rounds with the bullet I plan to shoot starting at the minimum powder charge and at the maximum overall length. Then I load 3 more but I add .3 grains of powder to the load and again at the maximum overall length. I do this, .3 of a grain at a time, until I start to see signs of pressure. I record the results then move on to the next powder and do the same. And once I find a load that has a SD I feel is small enough I start the load development.

With the same powder you will find a point where the SD numbers drop significantly. I think this is where the powder has reached is perfect efficiency. I have a 223 load that has a SD of 1.73 fps, which is amazing. I thought my chronograph was broke or the batteries were dead but after replacing the batteries it ran the same numbers again and again.

And because the bullet exits at a certain part of the whip you need to find the position where the bullet exits at the same time. I normally load the 3 that had the smallest SD. Then I load 3 more with the same charge except I seat the bullet .01" deeper in the case. Then 3 more that are .01" deeper than the previous. Seating .01" deeper will change where the bullet exits during the whip of the barrel. I will generally start out seating .01" and stop at .10". That is unless I see pressure signs first.

Then I take these loads and shoot them at a horizontal line on the target. I am not worried about lining up with a vertical line at this point. I try 100 or maybe even 200 yards. You are not worried about the horizontal, side to side, group size but vertical group size. That is if you have 3 rounds that are spread out over 2" vertically that means the bullets are exiting at different times during the whip. If you find that 3 rounds that are on that horizontal line, even if they are spread out horizontally, that means these are exiting very close to the same point during the whip.

I also prep my brass when I am trying to squeeze the absolute last amount of accuracy of the gun. I buy brand new brass and use brass from the same lot. I trim them all then weigh them all and throw out any out of the norm. Then I uniform the flash holes and chamfer the flash hole. I uniform the primer pockets so they are identical. Then I neck size the brass followed by body sizing the brass. And when seating my primers I seat them using a die that allows me to set the depth so all primers will be the same height.
For my Savages I set the headspace at 0 using the sized pieces of brass. That is I loosen the barrel nut and tighten the barrel down onto the sized piece of brass without anything providing some clearance, like tape or paper or gauges.

What did all this work get me? I have a factory Savage barrel that shot .3's at 100 yards pretty consistently. And those are 7 shot groups, not 3 or 5.

I haven't used this method for probably a year since I went to the 300 Blackout. I no longer shoot for the smallest groups on paper but do shoot for fun. I enjoy shooting clays and other reactive target so as long as my hand loads are able to that I am happy.
 

[jcluff]

I got out to the range yesterday and had an opportunity to put about 20 Winchester 55gr fmj through the barrel to measure when it starts to walk and found it a bit interesting. First 5-7 rounds grouped about 1.5-2 inches subsequent rounds seemed to walk down by another inch and then started walking to the right. I really wish I had video of it to replay.

Based on what I saw, I feel I should be able to get a 5 round group that performs consistently. The next 5 may open up a bit. After that, I expect the groups to really open up.

That said, being able to pull a consistent .8 inch group with 50gr AE varmint tipped is acceptable to me.

A friendly neighbor at the range, when listening to my woes over the barrel with heavier 77gr noslers, offered me three 77gr SMK loads that he shoots out of his custome and those three grouped just over .5 inches. He told me that his 1/8 twist barrels liked hotter loads and my barrel seemed to agree, so it may be time for me to up my powder.


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