Same Make/Model Question

[laweidauer]

My friend and I both bought Remington 700 Long Range Rifles chambered in 25-06. We bought them with little expectation that they would like the same ammo, but we both bought the rifle because we liked them and could always customize later off the 700 platform. We measured COAL on both rifles and they were within .001 of one another. Because they are so similar should we expect them to possibly like similar loads or will there still be several other variables that may make them different? Thanks in advance.

 

[Bart B]

The biggest variable will be their owners shooting them; even if both rifles were exactly the same for parts dimensions and fit parameters.

If both rifles were fired in a machine rest eliminating all external variables and with the same lot of ammo, one will probably shoot a little better than the other. Whether or not their owners shooting the same lot of ammo would show that is doubtful.

It takes test groups of at least 20 shots each to have a statistical confidence level of 90% meaning all 20 shot groups will be within 10% of their size in extreme spreads. 3- or 5-shot group comparisons are a crap shoot; you're rolling several pairs of dice and they all won't end up with 7's all the time. 7's represent the mid point of all the variables involved; snake eyes and box cars are the extremes. People, rifles and ammo all have variables. Best wishes in your endeavour to learn what each rifle really shoots that can be counted on all the time.

 

[barefooter56]

My friend and I both bought Remington 700 Long Range Rifles chambered in 25-06. We bought them with little expectation that they would like the same ammo, but we both bought the rifle because we liked them and could always customize later off the 700 platform. We measured COAL on both rifles and they were within .001 of one another. Because they are so similar should we expect them to possibly like similar loads or will there still be several other variables that may make them different? Thanks in advance.

Most probably not but you never know. I suggest you both follow a good barrel break in procedure. ( Kreiger ,Bartlein ETC have these posted on their websites for both stainless and chrome-moly barrels.)
Then get the bullets that you want to use that will work with the barrel twist rate of the rifles and start your load testing. I suggest you find your seating depth accuracy node using the lowest powder charge listed for the bullet/powder/cartridge combination you are testing. Once the seating depth accuracy node is found. Work your load back up in half grain increments until you get to two grains below maximum then drop to tenth or two tenth grain increments. All the while you will be checking for pressure signs and your accuracy. The biggest thing in testing is to ONLY CHANGE ONE THING AT A TIME as you do this testing and keep a good loading log book so you don't get "lost". Also there is plenty of good help to be found on this forum if you need it . Be safe! Have fun!

 

[bob4]

My friend and I both bought Remington 700 Long Range Rifles chambered in 25-06. We bought them with little expectation that they would like the same ammo, but we both bought the rifle because we liked them and could always customize later off the 700 platform. We measured COAL on both rifles and they were within .001 of one another. Because they are so similar should we expect them to possibly like similar loads or will there still be several other variables that may make them different? Thanks in advance.

A friend of mine and I have the same 700's in 300 WM. Had a low load mine loved. His shot a 3 inch group with that load. I wouldn't expect it.

 

[Bart B]

Shoot each other's rifle and ammo.

Do you think each rifle will shoot its ammo the same for both of you?

Better yet, do you both think all few-shot test groups with the same rifle and ammo will be the same size?

 

[barefooter56]

Shoot each other's rifle and ammo.

Do you think each rifle will shoot its ammo the same for both of you?

Better yet, do you both think all few-shot test groups with the same rifle and ammo will be the same size?

Bart B.,
If you try to shoot each others loads I suggest you each back the load off a grain or two and work back up. Don't just jump into it. One of you two or both may have an over pressure issue if you don't. As far as the groups being the same size. Chances are very slim . But you never know. Keep us in the lop with what you find please!

 

[Bart B]

Phil,

If there's enough difference between Remington's .25-06 barrels that one would shoot a given handload safe but another would have an over pressure issue with it, that's a sure sign of poor quality in Remington barrels. The same thing would happen shooting factory loads; one would have safe pressure and the other would not. That aside, the one with a tighter bore would be more accurate.

I didn't mean to do that, but to shoot both the other's rifle and its ammo to compare each person's shooting ability to see if that was the cause of different accuracy.

As far as groups being the same size, there's a 100% chance they will not. All of them will be between zero and some value. Nobody I know of has shot two or more few-shot groups all the same size; they're typically a 2X to 4X spread. But they've shot several 20-shot groups with the same stuff that are within 10% of the same size.

 

[barefooter56]

Phil,

If there's enough difference between Remington's .25-06 barrels that one would shoot a given handload safe but another would have an over pressure issue with it, that's a sure sign of poor quality in Remington barrels. The same thing would happen shooting factory loads; one would have safe pressure and the other would not. That aside, the one with a tighter bore would be more accurate.

I didn't mean to do that, but to shoot both the other's rifle and its ammo to compare each person's shooting ability to see if that was the cause of different accuracy.

As far as groups being the same size, there's a 100% chance they will not. All of them will be between zero and some value. Nobody I know of has shot two or more few-shot groups all the same size; they're typically a 2X to 4X spread. But they've shot several 20-shot groups with the same stuff that are within 10% of the same size.

Bart,
I see your point on the factory ammunition . But remember we are dealing with a SAMMI spec range of dimensions that, as long as a chamber falls in that range it is ok. If the rifle was chambered with a new reamer it would be on the large side of those SAMMI specs. If it was chambered with a reamer that was on its last use before going out of Sammi specs the chamber would be on the small side. A factory round in the first example would show less pressure than the second example because it can expand more. I have experienced a tenth of a grain difference in reloaded ammo making a reloaded round over pressure and blowing primers in a Rock River AR-15 while his friend who bought a Rock River AR-15 at the same time and place did not have this issue. Its not a quality issue its a tooling dimension issue IMHO. I know in the case of .308 Palma riles A TIGHT BORE was to accommodate some ammunition used in international competition before the throat length issue came along regarding the RADWAY GREEN ammunition. I dont know if a tight bore would be more accurate in every case though. The Sinclair F-TR team does not recommend using a tight bore (.299/.3065 ) but the standard .300/.308 bore dimension with Berger 185 Jug and 200 Hybrid and up until the last F-Class nationals they had won everything. I agree totally with the group size statement unless each rifle had its load tuned to its maximum accuracy. Even then there would be differences due to the largest intangible of all .. us. We all have different experiences in this sport. These are a couple of mine. Thats all.

 

[Bart B]

Phil,

I partially agree with your remarks on chamber dimensions.

I disagree with your group size statement even if each rifle had its load tuned to its best accuracy. Even then, there will be differences in few-shot group sizes in the 2X to 4X range (sometimes more) with the rifle fired in free recoil without any human intervention whatsoever. Biggest groups happen when all the ammo and rifle variables add up in all directions. Smallest groups when variables are at their minimum but pretty much cancel each other out. People shooting rail guns indoors where the atmosphere is very consistent see that happen with loads tuned to perfection. I've seen 10-shot 30 caliber 100-yard test targets from them ranging from sub 1/10th MOA to 3/10ths MOA. That's what the record 100-yard benchrest agg's are shooting loads tuned for best accuracy have done with several 5-shot and 10-shot groups. Groups with 5 or less shots typically have a greater spread in size than those with more shots.

 

[barefooter56]

Phil,

I partially agree with your remarks on chamber dimensions.

I disagree with your group size statement even if each rifle had its load tuned to its best accuracy. Even then, there will be differences in few-shot group sizes in the 2X to 4X range (sometimes more) with the rifle fired in free recoil without any human intervention whatsoever. Biggest groups happen when all the ammo and rifle variables add up in all directions. Smallest groups when variables are at their minimum but pretty much cancel each other out. People shooting rail guns indoors where the atmosphere is very consistent see that happen with loads tuned to perfection. I've seen 10-shot 30 caliber 100-yard test targets from them ranging from sub 1/10th MOA to 3/10ths MOA. That's what the record 100-yard benchrest agg's are shooting loads tuned for best accuracy have done with several 5-shot and 10-shot groups. Groups with 5 or less shots typically have a greater spread in size than those with more shots.

Interesting, Thanks Bart!

 

[Bart B]

Your "interesting" response is exactly what I thought when I learned the .0077" 5-shot hundred yard record group is held by a benchrest competitor who holds no other record.

How much smaller are the SAAMI spec .25-06 chamber diameters at minimum after the reamer starts out at maximum? I don't think they are enough to make a round go from safe to over pressure. What's' the upper limit for .25-06 pressure, anyway?

 

[barefooter56]

Your "interesting" response is exactly what I thought when I learned the .0077" 5-shot hundred yard record group is held by a benchrest competitor who holds no other record.

How much smaller are the SAAMI spec .25-06 chamber diameters at minimum after the reamer starts out at maximum? I don't think they are enough to make a round go from safe to over pressure. What's' the upper limit for .25-06 pressure, anyway?

The SAMMI website may have the information on the chamber specs and pressure. My thought is that you would have to throw the throat length v bullet type into the possible over pressure.

 

[Bart B]

The SAMMI website may have the information on the chamber specs and pressure.

Note that doesn't answer my question; but I already knew that.

You made a claim about pressure differences between SAAMI max and min chambers. Do you have any data to back it up?

I've shot the same loads in two different 24" barrels whose chamber dimensions were not exactly the same, but bore and groove ones were. Muzzle velocities for each was close enough that 1000 yard zeros were the same in come ups from 600 and 300. Therefore, I don't think the peak pressure difference was enough to get concerned about.

 

[barefooter56]

any difference in the loads?