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Producing Factory test results

2K views 19 replies 8 participants last post by  skwerl457 
#1 ·
It would be nice to reproduce results similar to the factory test target.

How many different lots and varieties were tested to get that one group?

My rifles are a JSR at about 6 pounds and a Montana Varminter at just under eight.

All I have been able to test so far is CenterX with lot numbers starting with 25, 26, 27, 28 and 29.
My "go to" ammo has been Remington Eley Match with a velocity of 1062.

The definition of "insanity" is being tested again and again.
 
#5 · (Edited)
Yes, they are test fired with the same stock that the rifle is shipped with. The test targets are fired in an enclosed 50 yard test tunnel. If they do not meet the test guarantee they are rebedded, rebarreled or whatever may be required to assure that they meet the company accuracty

drover
 
#11 · (Edited)
Individual results with an individual gun do not tell us much about the average of quality of that type of gun manufactured. Pick any respected product and you will, with a little research, find folks who had bad luck with that product. No manufacturer is immune from the occasional lemon. Cooper is a respected gun maker that by and large produces a very good product.

With all that said, I had the bad luck to come up with a lemon in my purchase of a Jackson Squirrel made in 2012. I purchased the gun second hand from an older man who was selling it at the Tulsa gun show. The gun had very nice wood, had box and papers, and looked ANIB. Close inspection showed little wear to the bolt mechanism. Since I had always wanted a Cooper and since the price was reasonable I purchased it. First test firing off my bench at fifty yards yielded the results below:



To say I was disappointed is an understatement...very poor accuracy and a lot of failure to fire incidents. Before someone mentions I needed better ammo or that I needed to practice more, I will say that I have been shooting off the bench for over forty years, and have won my share of matches. As to the ammo, all lots shown above gave good performance out of my Winchesters, Anschtuz, and CZ rifles. I was certainly hoping the Cooper would shoot at least as well as this little CZ 452 FS shooting mid grade ammo - all five shot groups:



But I didn't give up, I tried some lots of Eley match and some Midas +:



No joy. After much investigating I finally figured out the following problems:

a) the floorplate was inletted into the stock too far forward resulting in misalignment of the action screws and the barreled action. When tightened, this put abnormal stress on action and screws.

b) the firing pin was too short and the the bolt had excess headspace resulting in poor strikes and the ftf incidents.

c) when slugged, the bore opened up slightly at the muzzle....not a good thing.

There were some other issues, but the ones listed above easily explained the poor accuracy. I corrected the short firing pin with a new one and corrected the headspace. This resulted in an improvement in accuracy to the point where many folks might have been satisfied with it.....but not me.

The reason I was prompted to post here is due to the discussion about test targets and because of the test target that came with my gun:



I can't imagine how they got that gun to fire that test target considering everything that was wrong with the gun. I'm convinced the gun came that way from the factory based on it's near pristine condition when I purchased it. As I said, Cooper makes some excellent firearms, and I have no beef with the fact that I got a lemon....it happens. I would definitely try another JSR under the right circumstances. Bad luck on that gun though.

But I'll leave it to you to explain how that gun left the factory with that test target. :confused: :rolleyes:
 
#12 · (Edited)
That's exactly what I am talking about and what prompted me to ask how does Cooper get the powder burns off the target.:rolleyes: There was so much movement between the barrel and forestock on my rifle when I loosened the front action screw that I had to have the rifle Devcon bedded. I also suspected a headspace problem because I was having FTF too often. The firing pin protrusion is to the bolt nose. I have the bolt shimmed .006 and havent had a FTF since. I know this isn't a great way to fix a headspace problem, but without sending the rifle back to Cooper it was all I could do. How did you reduce the headspace on your rifle? Also, the bolt internals were so rough that it was causing firing pin spring drag. Had to hone that out. I have a Harrell tuner on my rifle and a Jard two ounce trigger. When shot at the factory I doubt any rifle has a tuner on it
,and no vertical stringing on any test target. Go figure. The scope is a March High Master 48x52 so I don't think that's the problem. The rest is a Pappas with a Fuzz Button top. I have tried Eley Tenex and Match, Lapua Xact and Midas Plus and RWS R 50. I'm not going to give up on this rifle, unless I go broke trying. A rebarrel probably would help, but who rebarrels a TRP-3?
 
#13 ·
I want to emphasize again that I am not posting to criticize Cooper rifles. But since the discussion here was about the test target, and I too had wondered about that, I decided to share my experiences. How did they get that test target with my gun....enquiring minds would like to know. :D

I too corrected the headspace problems with shims.....perhaps Kyoto shims...can't recall exactly. I think I also ended up using about .006" to correct the problem. You may know that some of the Suhl 150s had this issue, and the there was actually a guy who made shim kits to correct the problem. I had one of these Suhls and I used shims on it to correct the headspace. So, using them on the Cooper was no issue to me. By the way, I have been advised in the past that using shims is not a desirable way to correct the problem. But after running thousands of rounds through the Suhl with no appreciable wear to the shims, I decided it was no issue....at least for me. Certainly cheaper than removing the barrel and correcting it that way. Even though the gun was no longer warranted since I was not the original owner, I did talk with a very nice lady named Shirley (if my memory serves me) at Cooper who, after a little back and forth about my problems, kindly sent me a new firing pin....no charge. :bthumb:

Another issue developed with my Cooper after running a few hundred rounds through it. The inside of the receiver had some rough spots that galled and chafed the bolt surface pretty severely.

As to your gun and your attempts to solve the issues, I will say that I have purchased and traded for many guns over the years and sold a lot of them too. Many left because they didn't make the accuracy cut. I have found that if a gun doesn't meet expectations after a reasonable amount of testing and fiddling with, it is usually better to part company and move on.

As I have stated, every manufacturer is going to let one out occasionally that should not have seen the light of day....apparently I drew a short straw on the one I bought. That one should never have left the factory with all the issues it had. Sometimes quality control does an Uh-oh. On the other hand, there was a fellow that used to attend our matches. Shooting a Cooper (not a TRP, though it had a factory gray synthetic stock), he gave my Anschutz 1710 a run for the money in our factory class.

James
 
#14 ·
James, thanks for your reply. Reading the reply brought up another fix I have tried. When I shimmed my bolt 6 thousands I reduced the firing pin protrusion by the same amount. Since the Jard trigger doesn't have an adjustable trigger hanger I elongated the mounting holes a little to move the trigger to the rear. This increased the firing pin fall which also helped with the FTF. I'm not a gunsmith but I'm learning. I guess that's what you pay for when you get a full on custom built benchrest rifle built instead of a semi cstom built one. Les
 
#15 ·
I eventually sold that gun. When I sold it, it was shooting pretty well, but not well enough for my intended purpose.....shooting in club matches. I have even regretted selling it a few times since as it was a very nice looking gun, and I loved the way it handled and felt. Besides, I have a nice little Anschutz 1420 that has that same light handy feel to it.....and it is quiet accurate. But I knew I never would be happy with the Cooper. I did nothing to alter the stock or appearance of the gun in any way.

Its a shame to pay that much for a gun and have it disappoint that way, but that's the chances you take. Buying Anschutz or Cooper doesn't guarantee you will not get a lemon; it just increases the odds in your favor of getting a good one.

Good luck with your gun. Ultimately, I had to decide if I really wanted to modify the gun from it's factory condition (yes, I considered rebarreling) but finally decided to leave it factory and let someone else enjoy it.
 
#16 · (Edited)
James, something else that I'm going to try, that was suggested to me by a benchrest gunsmith, is to balance the rifle. Mine is front end heavy and it was suggested to get the balance point at the action face where the barrel attaches. He said that you could go even a little farther back of the action face. I'm waiting on a round tungsten rod that I will add to a hole drilled in the back of the stock. Not something that you would want to do to a sporter rifle. My rifle has the laminate stock and it won't be noticeable until you pick up the rifle. I'll post results when we get good weather to shoot.
 
#17 ·
James, something else that I'm going to try, that was suggested to me by a benchrest gunsmith, is to balance the rifle. Mine is front end heavy and it was suggested to get the balance point at the action face where the barrel attaches. He said that you could go even a little farther back of the action face. I'm waiting on a round tungsten rod that I will add to a hole drilled in the back of the stock. Not something that you would want to do to a sportier rifle. My rifle has the laminate stock and it won't be noticeable until you pick up the rifle. I'll post results when we get good weather to shoot.
Why would you use a tungsten rod ?
 
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