[beartracker]

Just started working with my 260 Rem. Need to adjust OAL for 125gr Partitions and 129gr SP but the 100gr SP is looking real good using H4350, Rem brass and Fed 210M primers. OAL 2.707" group size .201"

 

[pisgah]

I reckon that might do for plinkin'... ;-)

 

[beartracker]

I reckon that might do for plinkin'... ;-)

Yeah, I thought the samething

 

[broom_jm]

Let us know when you find a load it really likes, though...OK?

 

[beartracker]

Let us know when you find a load it really likes, though...OK?

No problem , I promise to let you know. The 125gr Partitions are moving at 3034fps and are 9/10 to 1 1/4" and the 129gr Spire points are moving at 2911fps and are 7/8 both are being pushed by Norma MRP.

 

[Tang]

Mike, you know how to ring'em out. Getting 3034 from a 125gr Partition, from such a small cartridge and a 22" barrel ? I say this, only because a 24" test barrel only produced 2876 for Hodgdon. The fastest load on Ammoguide, listed with a 24" barrel and a 120gr bullet is 2986, 2799 for a 130.

Edit: I found where it came from. The 6th Edition Nosler manual lists the 125gr Partition, with 48gr of N560 (112% case capacity), moving at 3034. But that was a 24" barrel also. If you got that from your 22", good job Mikey ! I know how much you love your load work. By the way, Norma MRP is just RL22. Seems a bit on the slow side for a .260, but you have been at this longer than I.

 

[beretzs]

I wouldn't think it is outta range, since he has a Shilen barrel, which may be a little faster than average. Plus MRP is a pretty quality powder, which is known to be pretty fast and used alot in WBY's factory stuff back in the day. Nosler is listing 2900 with RL15 and 4064, which are kind of a medium burning powder, I would think the 260 would use a slower powder for the heavier bullet weights. No clue, 2900-3000, either way, that is a good load. Scotty

 

[Tang]

I wouldn't think it is outta range, since he has a Shilen barrel, which may be a little faster than average. Plus MRP is a pretty quality powder, which is known to be pretty fast and used alot in WBY's factory stuff back in the day. Nosler is listing 2900 with RL15 and 4064, which are kind of a medium burning powder, I would think the 260 would use a slower powder for the heavier bullet weights. No clue, 2900-3000, either way, that is a good load. Scotty

Scotty, I was just asking because MRP is kind of slow. Not many people seem to know MRP and RL22 are one in the same. See the letter I posted above.

 

[beretzs]

Thanks for the heads up Ken. I did not know that either. RL22 is one of my favorite for the 7mm Rem Mag and 300 Win Mag. They shoot very fast and are usually pretty accurate. Thanks for posting the letter. That is pretty cool. Learn something new everyday.

If you want a good load for your 300 Win Mag, try a 200gr Accubond or 200gr Sierra GK. Work up to 73.5-74gr. I would be you will find a sub moa load that shoots around 2900 or better. It is very accurate in my Ruger M77RBZ 300WM and comes out the tube at 2950. Scotty

 

[beartracker]

Mike, you know how to ring'em out. Getting 3034 from a 125gr Partition, from such a small cartridge and a 22" barrel ? I say this, only because a 24" test barrel only produced 2876 for Hodgdon. The fastest load on Ammoguide, listed with a 24" barrel and a 120gr bullet is 2986, 2799 for a 130.

Edit: I found where it came from. The 6th Edition Nosler manual lists the 125gr Partition, with 48gr of N560 (112% case capacity), moving at 3034. But that was a 24" barrel also. If you got that from your 22", good job Mikey ! I know how much you love your load work. By the way, Norma MRP is just RL22. Seems a bit on the slow side for a .260, but you have been at this longer than I.

No, a better way of putting it is that RL-22 has a similar burn rate as MRP but it ain't MRP. In fact, Norma has been making MRP since I was a young lad, and Alliant is late on the seen with something very much like it but I can not get RL-22 to give me these velocities but I can get it with MRP. Similar but RL-22 ain't MRP. In fact with H4350 I have reach 3000fps with the 129gr Spire Point but it was not accurate.

 

[Tang]

If you read that letter (what you can see of it), you will see they are made by the same company.

 

[beartracker]

I read the letter and I know what happens at the bench and across my chrony. I never have the lot to lot variation with MRP that I have with RL-22. I have had 10% variation in load charge with RL-22 and never had that with MRP. Now we are talking 20yrs of working with MRP and 15yrs with RL-22 in a multitude of cartridges.

Point in case I could not load the same charge of RL-22 and MRP in my 260 load before reaching pressure problems with the RL-22. The RL-22 was a hotter Lot. Now you can ramble on for next year about this but it will not change what I have noticed for all the years I have used both. Experience is a much better teacher than theory, you ought to try it, you might discover you don't know it all.

If you think that Norma does not require a certain specification on their powder from the maker you are truly mistaken. Plus Norma test every lot sent to them to see if it meets their specifications for rate of burn and stability. Only then is it accepted by Norma. That is why I have experienced the difference between the two. You will also note with certain software for load development that they are not always neck and neck. Norma requires a higher standard and the there is a difference. Hey, you and I are friends and have been for a long time. So lets not get in a spitting contest over this. I am set in my ways due to my results over the years and my record keeping which shows the difference in my experience.

 

[dmsbandit]

Scotty, I was just asking because MRP is kind of slow. Not many people seem to know MRP and RL22 are one in the same. See the letter I posted above.

My 260 model 7 with 18.5" barrel shoots it's best groups with 129 Hornady SP when sitting over Winchester WXR. That is also a different lot of rel-22.

 

[M1Garand]

If you read that letter (what you can see of it), you will see they are made by the same company.

I've seen that letter and have heard the same and that the difference was MRP had better QC then RL22. I've also heard they were the same but with a different coating which would alter the burn rate, therefore making it different.

 

[EWestbrook]

Here Chucky has someone talking about burn rate.

http://www.chuckhawks.com/powder_burn_rate.htm