Jump on 30 cal 165gr. PT

[3deers]

Recently, I had to change primers because of unavailability of CCI 250 in my area.
So I switched to Win LRM.

I am loading the 165 Partition, 308 Win, Rem brass, 45.5 - 47.5 gr Win748. The CCI primered load was pretty hot at 47gr. The Win primers are showing no signs of pressure whatsoever at 47.5. Unfortunately, I no longer have access to a Chronograph, so I cant compare velocities.

The initial groups don't seem to be as tight as with the CCI250 primers, not 47gr or 47.5gr. The CCI load was always MOA or a bit less. The Win-primered load seems to be in the 1-1/2 to 1-3/4" area. Still have some more groups to shoot, but here's my question:

What is the general consensus on distance from the lands with Partition bullets?
Most of my loads have been .010" off. I've been seeing the posts of the AccuBond recommendations of .100 off and I'm just wondering if I should be changing my train of thought. Any comments are appreciated.

 

[DrMike]

I've always treated Partitions as cup-and-core bullets, seating them relatively close to the lands. Most of my Partition loads are at or near 0.010 inches off the lands. I am not certain as to the reason that in general bonded core bullets appear to prefer a much longer jump to the lands, but that is my general observation. WLR primers were once considered a primer with the most brisance. Whether they have more brisance than CCI250s is debatable. I'm going to guess that in your load they are still giving you complete ignition, but they will not generate as much pressure in the initial ignition phase of burn. Consequently, you will be able to load somewhat more powder in order to obtain the same velocity.

 

[hubcap]

I have tried using plenty of jump with PT,s. Accuracy always suffered. I no longer bother to even experiment with it. With Pt,s I just load em .010 to .025 and always seem to be very happy with them. With AB,s I usually end up with a lot more jump.

 

[joelkdouglas]

Same here, I normally start them between 0.02 and 0.03 off.

 

[Guy Miner]

Those 165 gr Partitions really surprised me with their accuracy when I loaded some up for my .308 "Green Machine" with the Krieger barrel.

I literally just substituted the 165 Partition for the 168 gr match bullet I usually load. Everything else stayed the same: Federal Gold Medal case, Federal 210 match primer, near-max load of Varget... I just load them to mag length in the short action Rem 700.

Zing! Easily under MOA at 100, 200, 300 and 400 yards. Approaching 1/2 MOA... I don't have the measurements anymore, but I was more than pleased.

I did not expect such accuracy from a dual-core soft nose hunting bullet...

Guy

 

[3deers]

Thank you all for your input.

I guess I'll trust and stick to the .010" off that I've been using, and just do a bit of tweaking with the charge. There looked like some promise at the 46.0 gr mark.

 

[MrMinks2]

I've always had the best results with IMR 4350. You ay give that powder a try.

 

[Guy Miner]

I've always had the best results with IMR 4350. You ay give that powder a try.

In the .308 Winchester?

Guy

 

[MrMinks2]

I've always had the best results with IMR 4350. You ay give that powder a try.

<br abp="753"><br abp="754">In the .308 Winchester? <br abp="755"><br abp="756">Guy

I've always had the best results with IMR 4350. You ay give that powder a try.

In the .308 Winchester?

Guy

Oops! .30-06.

 

[Guy Miner]

Ah! Now, that makes sense!

Agree, 4350 is a mighty fine powder for the .30-06 cartridge. Absolutely!

Guy

 

[Vince]

I like 4350 with 180 grain bullets in the 30-06.

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