Imr4895/h4895

[phil evans]

hornaday's 5th edition handloading, in their garand 30-06 section, page 366, shows for a 155 grain bullet use 46.4 grains of IMR4895 as a maximum load for velocity of 2600.
american rifleman, march 1986, page 50 states 48.5 grains of IMR4895 for a 150 grain bullet for velocity of 2655.

why this large two grain discrepancy - for the same velocity?
burn rate number on hornaday's chart is 66 for IMR 4895 and 68 for H 4895.
are modern books cautious due to potential litigation.

Information

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[JohnMOhio]

Phil, I could be wrong on this but as I understand it, the powder characteristics of powders have changed over the years. I can go back to some old reloading books and find that some of the starting rates back then are very near the max amounts today as the powders have been improved. The powder of today may have the same name like IMR 4895, but it is not your fathers powder. That is the best way I can describe the difference. I am sure someone with better knowledge of powders will chime in on this and can be mores specific.

[rider]

Hodgdon's chart has H-4895 at #69 and IMR-4895 at #71.
Two different sources come from two different labs, two different test barrels, different lots of powder, different bullets, probably different primers and possibly different decades or millenia. Modern books are new and old data is old. If you start with maximum loads, you're going backwards. Find some current data and work up your loads. Buy a Reloading Manual that explains high pressure and its signs. If you think that a bunch of lawyers are dictating what appears in your Reloading Manual, go ahead and ignore the max load and start looking for pierced or blown primers, blown cases or maybe a blown rifle. HTH

[Griff Murphey]

Let me say first of all that my loads are all mild loads and I never go to max loads. I sometimes use old loading data but I always cross-check with a modern book. My opinion, which is only anecdotal, is that Hornady IMRs are a bit hotter than the old DuPont IMRs.

[USSR]

hornaday's 5th edition handloading, in their garand 30-06 section, page 366, shows for a 155 grain bullet use 46.4 grains of IMR4895 as a maximum load for velocity of 2600.
american rifleman, march 1986, page 50 states 48.5 grains of IMR4895 for a 150 grain bullet for velocity of 2655.

why this large two grain discrepancy - for the same velocity?
burn rate number on hornaday's chart is 66 for IMR 4895 and 68 for H 4895.
are modern books cautious due to potential litigation.

"are modern books cautious due to potential litigation"; you betcha. IMHO, the American Rifleman load is a much more realistic load. My Garand load for a 144gr FMJBT bullet is 49.5gr of IMR4895. For your 155gr bullet, I would would start at 47.0gr of IMR4895 and work up from there.

Don

[TDH]

For 30.06 for my 03a3 I use 47 grains of IMR 4895 or H if I'm out of the IMR. Both puts me in the low to mid range of the loading data I have available and it works real well with either the 147 or 168 grain bullets. For my LN 03 I drop the number down to 44.4 grains of powder which is very low end. And the rifle shoots good. And for all those of you that are having kittens about me shooting a LN I tell anyone near me when I shoot those 50 rounds a year what it is and what I'm doing. If it blows then I'd rather go that way than wasting away in a hospital bed 60 years or so from now. OH yeah I'm pushing 60 now.

[phil evans]

i've never loaded max in my 45 years of reloading, always plain vanilla, 9mm, .38spl, .243(.551 MOA, .308(.235moa), 30-06(1.684MOA).
been using 45.5 grain both for varget(2389vel.) and blc-2(2446vel),
used schhuster but do not know if i like it or not like it; its useful but maybe not really useful.
main concern is: operating rod @ $250.

[slamfire1]

The 2001 Camp Perry John Garand ammo was clocking hot, might have been 2800-2900 fps. Friends chronographed the ammo but I forget. Anyway folks had malfunctions all along the line. Clips partially ejecting, operating rod dismounts, etc. The next year the issue150 grain ammo clocked 2699 fps in a 26" match barrel. Everything worked as it should

Different barrels will give different velocities. As you can see with the same load, different 24" barrels, one is faster than the other.

In a 26" match barrel, TW56 ball is only moving at 2680 fps. In a 24" Garand barrel it should be moving less.

For me, in a Garand, 47.5 grains IMR 4895 with a 150 bullet is my maximum.

SAKO   24" Barrel   					
								
150 gr Sierra Match HPBT 47. 5 IMR 4895 CCI#34   WWII cases OAL 3.290"		
17-Aug-06	T = 85 °F	 					
Ave Vel =2703	 				
Std Dev =26.41	 				
ES =	80.66	 						
High =	2739	 						
Low =	2659	 		 		 		
N =	10	 			 			
	 							
M1 Garand  5 827 XXX Rack Grade, GI Barrel				
								
								
150 gr Sierra Match HPBT 47.5 IMR 4895 CCI#34  WWII  cases OAL 3.290"		
24 Mar 04	  T= 70 ° F	
								
Ave Vel =2619						
Std Dev =28						
ES =	101							
Low =	2559							
High =	2660							
N =	16							

[Publius]

I shot the JCG match in '01. The ammo was Federal IIRC. They had no problem in my H&R I had just bought for the match. I am partial to 4895 for all military calibers. My 1000 yd .223 hand loads use 4895.

[Gyrene]

It is a good idea to have several recent reloading manuals. While I have never seen it, there is always the possibility of a unintentional error in any technical manual. With 3 or more manuals, a misprint would be clearly at odds with the majority.

Gyrene OFC

semper fi

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