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Loading for DPMS 308/260
tsr1965
Member Posts: 8,682 ✭✭
I was wondering what anyone's experience is with loading for the DPMS LR-308 or LR-260. Do you have to use the small base dies, and what powders work best for accuracy and operation of the action.
Best
Best
Comments
I do not know much about the .260 so I am no help there.
As for the .308 I would try your FL dies first, if you have them. I am not sure how tight the chamber is that DPMS puts out. One of the reasons for the SB dies is to make it "more" reliable. I have heard many people have very good luck with FL dies and if you are not using this as a "defensive" rifle if you have a round along the way that does not chamber is it a big deal?
As for powder on the .308 I am sure they were built to run best on military loads. I would start there and adjust as needed.
When I originally tested these rifles, I used the Federal Gold Medal Match exclusively simply because it's considered to be a standard. The load I used most was with the 175 gr. MK as the 168 gr. never thrilled me in the least. These loads run about 2600 FPS from the factory based on their test barrel. Your velocity will vary of course.
I did not use the FGMM for reloading since the brass is too soft to depend on. I used Winchester brass, Berger VLDs and one of three powders based on a slightly faster pressure curve:
IMR-3031
AA MXR-2495
V V N-135
Best.
tsr1965,
When I originally tested these rifles, I used the Federal Gold Medal Match exclusively simply because it's considered to be a standard. The load I used most was with the 175 gr. MK as the 168 gr. never thrilled me in the least. These loads run about 2600 FPS from the factory based on their test barrel. Your velocity will vary of course.
I did not use the FGMM for reloading since the brass is too soft to depend on. I used Winchester brass, Berger VLDs and one of three powders based on a slightly faster pressure curve:
IMR-3031
AA MXR-2495
V V N-135
Best.
Nononsense,
Did you have to use the small base dies, or did the rifle function OK with FL dies?
Best
Sorry, I forgot that part...
The Federal GMM always needed the SB dies.
The Winchester worked fine with standard full length dies so long as they were made correctly. I'm not anywhere close to the notes I need to answer this absolutely but I think I was using a set of Forster Benchrest dies for this set of tests.
All of this is dependent on the way the chamber was cut, the type of steel being used, cryo'd or not and the specifications at the time the dies were being made. These days, I would cast the chamber, measure carefully and order the type of dies required for the chamber.
Best.
tsr1965,
Sorry, I forgot that part...
The Federal GMM always needed the SB dies.
The Winchester worked fine with standard full length dies so long as they were made correctly. I'm not anywhere close to the notes I need to answer this absolutely but I think I was using a set of Forster Benchrest dies for this set of tests.
All of this is dependent on the way the chamber was cut, the type of steel being used, cryo'd or not and the specifications at the time the dies were being made. These days, I would cast the chamber, measure carefully and order the type of dies required for the chamber.
Best.
I have all 3 types from RCBS...Neck, FL, and SB. If I need to get a set from Forster for Benchrest I will do that. Thanks for the heads up with the FGMM. How do the AMAX bullets do compared to the MK? I'm not going to be doing any match shooting, but do plan on taking a deer or two out to 500-600 yards, provided I get the accuracy performance I need. I really wanted a 260, and will get an upper when they become available.
Try the dies you have first then buy others if needed. You don't have to waste money if the ones you have will do the job right. RCBS makes good dies most of time. The only thing I suggest is to check the concentricity of the body to the neck in the dies.
" How do the AMAX bullets do compared to the MK?"
That's a good question.
I prefer the AMAX bullets in most situations with the following disclaimer. The newer versions of the MK will give you a more round group at longer distances, consistently on paper. The AMAX are more accurate when 'X' counts don't matter. I also prefer the performance of the AMAX on tissue at the longer distances. My last 3 Coues deer have been harvested with 6mm 105 gr. AMAX bullets at ranges running a pinch longer than 500 yards. No running, not a lot of meat damage and good performance. Don't do like the magazines tell you and go for the shoulder. Take your time and make a good heart or neck shot and go collect your meat.
For the .308 Win. you can try the 178 gr. AMAX and see if you can get it to about 2600 FPS using IMR-4895. It should make a pretty good deer getter with a high probability of top accuracy.
Best.
First I want to thank you once again for your insight, mostly due to your experience in testing, and your willingness to share your results with others. It is appreciated on this end.
Last, one more question. In your testing the AR platform, what did you have for a trigger? Was it a two stage, a reworked standard AR trigger, or an aftermarket drop in? If the latter, what brand and model?
Best
Twice fired Federal GMM brass
Full length sized on a Redding FL Small Base Die(Standard dies do not work with my chamber)
Trimmed to 2.007"
Primer pocket cleaned
Flash hole deburred
Case mouth deburred and chamfered
Cases polished
CCI#34 primers
175grn Sierra BTHP's
Loaded to mag length
The powder was weighed using a dipper onto the pan of a RCBS 550 and trickled to finish. The bullets were pushed in with a Forster mic. seating die. The distance was 100yds and it was about 35F with no wind and full sun. I used a Ledsled DFT. I'm sure about three of the groups have one shot that I * the trigger on so one of the groups I measured the four shot group and the five shot group. I am using the stock DPMS trigger that was measured at 8.3lbs, pittiful. On any given day these groups could have been a little better or a little worse, but all in all I'd say the rifle likes a few different loads and shoots pretty well
I know I pulled the stray in this frame, I called it.[:(]
All of our rifles are different and of course always consult your reloading manual before starting.
Now you're really testing my memory.
If I am remembering right, the 3 of us shooting these tests got fed up with the factory trigger on one of the rifles and tore it out after about 50 shots. We replaced it with either a JARD or JP trigger set for about 3 lbs. which I think they refer to as the Competition model. Much better! You could probably make a less expensive trigger work as well but one of us had this on a bench.
Best.
tsr1965,
Now you're really testing my memory.
If I am remembering right, the 3 of us shooting these tests got fed up with the factory trigger on one of the rifles and tore it out after about 50 shots. We replaced it with either a JARD or JP trigger set for about 3 lbs. which I think they refer to as the Competition model. Much better! You could probably make a less expensive trigger work as well but one of us had this on a bench.
Best.
I think JARD makes one that is a single stage drop in that you can get in either 2 or 3 lbs. I have fired an AR-15 with the JP 2 stage that was nice also. I have currently changed the geometry of the factory trigger for a safe 3 lbs, but it still has too much sear engagement(@0.030" at the trigger), and I am not comfortable with getting rid of it. But I did like that JP. If I am not mistaken, there is someone who makes a set trigger for the AR platform.