175smk's 0.005" off the lands??

[kwild]

I have been loading my 175's to max mag length with fairly good success. I loaded up 10 rounds today that are about 0.005" off the lands. Has anyone run these bullets this long in a 308 with good success? Wont be hitting the range till later this week. Just courious to see everyones results. The coal I am running them at is 2.894" with 44.5gr of RE-15.

My plan is to try these and see if they shoot better being closer to the lands. If they do then I can get longer mags and use these in my tikka. I have done the research and I can use a 30-06 tikka mag instead of my 308.

 

[Shady_Jay]

Re: 175smk's 0.005" off the lands??

175's are forgiving and can run with quite a bit of jump. The only way you will know if your load likes .005 off the lands is to shoot them and find out.

Seating depth and powder charge usually go hand in hand. If it shoots like crap, you probably need to adjust the charge. FWIW

 

[desertHK]

Re: 175smk's 0.005" off the lands??

What stick are you shooting it with? At 2.894", you are 0.005" off the lands? Wow, that's a short chamber. I load my 175 to 2.900" and still has about 0.020" to go. Let us know with the range report.

 

[kwild]

Re: 175smk's 0.005" off the lands??

I thought I would be going longer too but the bullet touches at 2.900" It is a tikka tactical.

 

[desertHK]

Re: 175smk's 0.005" off the lands??

I am a bit surprised. My old Remy has a chamber length of about 2.970" for the 175 SMK.

 

[Wil]

Re: 175smk's 0.005" off the lands??

take heed to CKA's post...

he's loaded & shot a few 175s... <grin>

 

[sobrbiker883]

Re: 175smk's 0.005" off the lands??

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: DesertHK</div><div class="ubbcode-body">I am a bit surprised. My old Remy has a chamber length of about 2.970" for the 175 SMK. </div></div>

Remington is known for "Linda Lovelace" throats. Salvages will usually have longer mag boxes and shorter throats-it'd be nice if Remington did as well. My guess would be that some lawyer did a risk analysis: if the home handloader can reach the lands with a mag length round, then there'd be no liability that could be tossed back on Remmy for an overpressure catastrophe.

My Rock was cut with an Obermeyer chamber for SMK's. Prior to any throat erosion, 2.840" OAL is at the lands with 175's (2.830" with 168's).

 

[minnesotadan]

Re: 175smk's 0.005" off the lands??

I can run the at an OAL of 2.90 in my AIAW, I find my best groups at 2.82 OAL with a .023 MOA at 300 yards. I see no reason to change.

Dan

 

[Greg Langelius *]

Re: 175smk's 0.005" off the lands??

Bullet seating is a sorta binary question to me. They're either in the lands, or they'r not. All in, good, all out, also good, some in, some out, not so good.

Because of typical production QC issues, ogive length dimensions vary enough that .005" becomes a somewhat optimistic goal, IMHO. I would never attempt to seat bullets any closer than .010" to the lands, if I wanted them all to jump. Closer than that, and I'd be uncertain whether they were all jumping.

Greg

 

[BLAWTON]

Re: 175smk's 0.005" off the lands??

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">Bullet seating is a sorta binary question to me. They're either in the lands, or they'r not. All in, good, all out, also good, some in, some out, not so good.

Because of typical production QC issues, ogive length dimensions vary enough that .005" becomes a somewhat optimistic goal, IMHO. I would never attempt to seat bullets any closer than .010" to the lands, if I wanted them all to jump. Closer than that, and I'd be uncertain whether they were all jumping or use a o-jive size bullet seater.

Greg </div></div>

Thats a some good points greg. Thats why i sort my bullets or buy ones that dont need sorted. Sometimes they like it just a few thou off on it in the lands but thats pointless if you dont sort the bullets.

 

[insight3b]

Re: 175smk's 0.005" off the lands??

What 'Greg' said but I add:
Through my home built M24 clone(LA) I can seat the 175smk much more shallow. For my VLS and M21 I run 'em to 2.80 and with 41.2gr of VV N540 lit with a CCI 200 in LC brass I get 1moa through both rifles out to three(the furthest distance availble) I feel lucky to have two rifles that like the same load this much.

 

[swarrick]

Re: 175smk's 0.005" off the lands??

I have ran the 175 from .005 to .018 off the lands and they shoot good. I recently started running them MUCH further off the land and actually load the to 2.220 (Ogive). The reason was when my rifle was built, the feed ramp was not trimmed to match the length of a AI mag. If I loaded to .018 off and then chamber a round from the mag the tip gets hung up on the bottom side of the action and screws up the works. So I load to the 2.815 COAL or 2.220 ogive and they shoot damn GOOD. So I see no reason to get any closer but like stated above I did have to jack with the powder charge a bit.

 

[sobrbiker883]

Re: 175smk's 0.005" off the lands??

No dremel Steve? I run my 175's at 2.830" oal (2.335 ogive). THis is .010" off the lands in my chamber.

They fit fine in the action and AICS mag, but if the mag gets bumped they can hang under the receiver. I blew stages in 2 matches from it and broke out the hand mill.
Any oal can do this if the rounds slide forward in the mag unless the receiver is relieved (which reminds me, I gotta do my 7-08's receiver too).
See ya this weekend!

 

[MitchAlsup]

Re: 175smk's 0.005" off the lands??

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">Bullet seating is a sorta binary question to me. They're either in the lands, or they'r not. All in, good, all out, also good, some in, some out, not so good.

Because of typical production QC issues, ogive length dimensions vary enough that .005" becomes a somewhat optimistic goal, IMHO. I would never attempt to seat bullets any closer than .010" to the lands, if I wanted them all to jump. Closer than that, and I'd be uncertain whether they were all jumping.</div></div>

I agree with Greg. Either seat the bullet into the lands, or away from the lands.

Taking temperature into effect, there can be a shrinkage of the case OAL if your reloading station is warm and the FFP is cold. There can be an expansion if the opposite holds. For the size of cartirges we typically shoot around here one can see a 0.005" change in OAL dimension over reasonable environmental temperatures {i.e. not the south pole but at least hunting conditions, and not Death Valley in August but usefully warm like anywhere outside in Texas in August}.

Thus to ensure that those cartriges loaded to be at the lands at the FFP, one needs to be 0.005 into the lands at the reloading station. And to ensure that those laoded to have a jump to the lands need to have that jump and the 0.005 tollerance at the reloading station.

The only time this is not necessary is when the reloading station is besides the FFP and thus the delta-T is zero.

 

[kwild]

Re: 175smk's 0.005" off the lands??

Well I finally got out yesterday to shoot these ten rounds. They had no advantage over my loaded to max length loads. Both shot well. I guess that will save me some money as i wont have to buy longer mags lol. I am sure I could play with the tiniest of details to get them even tighter but not sure if it is worth my time or not. I am getting .5 moa with them now if I really take my time and dont rush the shot.