They'll be around eventually. Things are showing up. Just kinda wanted 100 for this new rifle for testing. They are very low priced bullets and well built. I shoot the 160 version in my .284s and they are excellent deer bullets.
257 Bob Accuracy loads
- Thread starter Frankm
- Start date
Murray Brook
Silver $$ Contributor
Most certainly agree. I use their 145 SBT in my 7/08. Great accuracy and very good on deer sized game as well as being priced right.
My fireforming load for my Ackley-Bob is definitely on the hot end, for the standard chambering, since I’m moving the shoulder. For this reason I’m not posting the charge weight.
WW brass
H4350 (north of book max)
Horndaddy 117SST
WLR Primer
MV = 2890ish (25”), ~1/2MOA @ 400yds
My recommendation is to run near, but comfortably below, max pressure. Ideally running 2760-2775 or 2820-2830. From there, play with seating depth. This is for the heavier .257 bullets. If you want to run a light bullet fast, target 3080fps.
I have a theory about atmospheric transition turbulence (my terminology). Seems that a vast majority of bullets like to leave the barrel at certain speeds regardless of barrel length & profile, or bullet caliber, weight, & shape.
WW brass
H4350 (north of book max)
Horndaddy 117SST
WLR Primer
MV = 2890ish (25”), ~1/2MOA @ 400yds
My recommendation is to run near, but comfortably below, max pressure. Ideally running 2760-2775 or 2820-2830. From there, play with seating depth. This is for the heavier .257 bullets. If you want to run a light bullet fast, target 3080fps.
I have a theory about atmospheric transition turbulence (my terminology). Seems that a vast majority of bullets like to leave the barrel at certain speeds regardless of barrel length & profile, or bullet caliber, weight, & shape.
I have a Roberts in a Ruger 77 Mk 11 with extended throat. Maximum OAL kissing lands is 3.035 inches. R-P cases, WLR primer, 44.5 gr H4350, 110 gr Hornady ELD-X , COAL 2.980 inches. 3 shot average 1/2 MOA.
Kurz
Silver $$ Contributor
Originally, we chambered the .257 Roberts in 'intermediate length' Mauser actions which were plentiful at the time. The magazine lengths varied from 3.115" to 3.232" depending on the model. This is very nearly ideal for the x57 cartridges as proven by the Germans and Belgians. Going longer solved nothing and the American adapted length of 2.775" for short actions simply curtailed the case capacity by deep seating the longer, heavier bullets.
The Rem. M721, being a long action with an unknown box length, might do better with the slightly longer seating but will necessarily be based on the chamber design.
Here are 300 loads from a Handloader article:
https://www.handloadermagazine.com/257-roberts-p-pet-loads
On my current version of the .257 Roberts, I'm using the Defiance XM version with a magazine length of 3.200" OAL and a load length of 3.100". Loading the 115 gr. Nosler Ballistic Tip and the Berger 115 gr. VLD, I'm very near to the 3,000 fps when using Hybrid 100V. This from a 24" barrel.
In reality, but with no bearing on the OP, I prefer the Ackley Improved version of the Roberts.
Enjoy!
The Rem. M721, being a long action with an unknown box length, might do better with the slightly longer seating but will necessarily be based on the chamber design.
Here are 300 loads from a Handloader article:
https://www.handloadermagazine.com/257-roberts-p-pet-loads
On my current version of the .257 Roberts, I'm using the Defiance XM version with a magazine length of 3.200" OAL and a load length of 3.100". Loading the 115 gr. Nosler Ballistic Tip and the Berger 115 gr. VLD, I'm very near to the 3,000 fps when using Hybrid 100V. This from a 24" barrel.
In reality, but with no bearing on the OP, I prefer the Ackley Improved version of the Roberts.
Enjoy!
Orr89rocz
Silver $$ Contributor
Problem i had with my 257 roberts is it seems short throated. My mag length allows me to go to 2.97” oal but with 117 btsp hornady or even the 110 game changers, i cant get near that length before crashing into the lands... ER Shaw made the barrel so might be their reamer spec but it should be sammi spec. Im sure i could hit that length or more with a 115 berger vld or maybe the 110 eld-x im not sure.
Are you guys getting different free bore lengths or do they vary much?
Are you guys getting different free bore lengths or do they vary much?
Kurz
Silver $$ Contributor
SAAMI specifications are available online. Here is the .257 Roberts:
Note that the MAX OAL is 2.780" in the top cartridge drawing. But it is not just the basic length of a bullet in this case but the shape of the bullet which can contact the throat. Take out a Spitzer bullet and set it next to a VLD bullet of the same weight.
Note that the MAX OAL is 2.780" in the top cartridge drawing. But it is not just the basic length of a bullet in this case but the shape of the bullet which can contact the throat. Take out a Spitzer bullet and set it next to a VLD bullet of the same weight.
Infrequent Shooter
Gold $$ Contributor
were the 110 gr tip game changers the most accurate bullet you have found?
Orr89rocz
Silver $$ Contributor
Those were the only 2 i tried in it. I moved on to working on a couple other rifles. I got some new brass and dies i wanna use so i may revisit it with some light ttsx coppers or the 115 bergers
Infrequent Shooter
Gold $$ Contributor
Thank you, Orr89. I am going to try the Hornady 110 eld. and the 117 gr SST. I have fired a factory 7-08 SST bullet and it was very accurate in a HB Savage. (it had BC of 486).
Infrequent Shooter
Gold $$ Contributor
what was the most accurate bullet in your 25 caliber rifle(s)?
Kurz
Silver $$ Contributor
Since my response 2+ years ago, I have tested several other bullets with varying results.
My current preference for a mild pressure load is the Badlands 110 gr. Super BD2 loaded to 3.175" for my less modern actions. This runs about 50,000 PSI but will perform numerically out to about 700 yards if you can manage that distance.
My Defiance XM action usually will perform at a higher pressure rating with a 26" barrel. I still use the Badlands bullet but I also continue to use the 131 gr. Blackjack bullet as well. Both are very accurate and my supply of the 131s is still substantial so no worries about running out.
My current preference for a mild pressure load is the Badlands 110 gr. Super BD2 loaded to 3.175" for my less modern actions. This runs about 50,000 PSI but will perform numerically out to about 700 yards if you can manage that distance.
My Defiance XM action usually will perform at a higher pressure rating with a 26" barrel. I still use the Badlands bullet but I also continue to use the 131 gr. Blackjack bullet as well. Both are very accurate and my supply of the 131s is still substantial so no worries about running out.
Infrequent Shooter
Gold $$ Contributor
Kurz, great info and thanks.
long40shot
Gold $$ Contributor
I have a Bob improved. I like the 110s over H4350. Good stuff!
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