I got some new bullets in the mail today before my dies i want to go to the range NOW

[Bennybone]

So I am thinking of using a kinetic bullet puller on some AA 129 SST loads and pressing in the 140gr Speer FB bullets.

I used a vice to push the bullet into the case. I cannot crimp and there is no cannelure.

The brass is pre formed to the chamber spec by the factory loading and I am going to test 5 rounds.

Once the dies arrive in the future I will try various load developments with commercially available powders.

The point to this test is to determine if an accurate load is sitting right under my nose from the get-go! I do have approximately 100 rounds of AA factory loaded ammo and so if this experiment works I would rather swap the projectiles and hunt in the short distances with the Speer bullet.

BB

[bwaites]

That should not be an issue, although if the bullets stick in the lands there is a chance that you will pull the bullet out of the case if you have to eject a full cartridge.

PS... Good luck with a kinetic puller and factory ammo, I couldn't make it happen and had to use a Hornady puller.

[Deezil]

I pulled one hornady 123 amax factory ammo, had to hit it pretty good on a cement floor.

Looking forward to some range reports!

[Bennybone]

cautiously proceeding

I am just swapping bullets between Alexander Arms 129gr SST factory loads and the Speer Deepcurl 140gr projectile.



Side to Side the 129gr SST is longer



The nose end



I slapped 5 rounds of the SST around until the bullets and powder came free. I had taken a measurement of powder in the original case and it was 26+ grains. I went with a flat 25 grains of whatever powder is in the factory ammo and pressed in the Deepcurl to the same COAL as the SST.



I am hoping that 25grs and correct COAL is a safe start to this swap, I know that generally powder weights are reduced as you step up the bullet weight.

So the rule of thumb I went by is that typical 120 gr loads are max 29gr and 129 gr loads have an average max of around 27.3gr so I reduced by a similar weight to the 140 gr amount.

Lastly the 140gr recommendation from Alexander Arms for the Lapua Nautalus is around 26.5 grains.

IF this round shoots decent I would only use it for 200 yard or less hunting situations.

To be continued.....

BB

[Drifter]

I would have to hold off on such an experiment. Using an unknown powder without properly working up a load could be very dangerous, not to mention that some powder may reside in the case unknowingly. Even if you proceed and no harm is done, not sure that you'll accomplish much, as the powder in the case is likely unavailable and you'll still have to work up loads using a different propellent.

My advice is to be patient, and above all, be safe.

[txgunner00]

In my experience, COAL's are very different for different bullets in a grendel. Just from looking at your picture you may have issues with the ogive of the new bullet contacting the lands which could lead to pressure spikes. Color one of the new projectiles with a sharpie and manually chamber it. Rifling marks will usually show if it makes contact.

[LRRPF52]

Since the new bullet...

Takes up more case capacity, volume is decreased....pressure rises

Has more bearing surface, there is more resistance....and more pressure

IS heavier, there is more resistance....and more pressure

Since we don't know what powder is used, it may be one specifically developed for the 129 SST, and who knows how it will behave with these 140gr pills.

If you do go forward with this load, wear some good gloves, heavy jacket, ballistic eye protection, and keep your extremities away from the bottom of the mag well, whatever you do. I would actually keep all body parts no further than the pistol grip.

Fire only one round, and look at the spent case immediately, without firing another. Check for blown primer, excessive obturation of the case head, black eschar, cracks, extreme ejector extrusion.

I'm saying this cause I just did it with a .260 Rem and some experimental solids, and blew the crap out of some primers...vaporized them. The AR10 action can take this kind of beating and smile, but the AR15 can't, especially with a modified 5.56 bolt that has been opened up for a larger case head.

[Bennybone]

still proceeding ever more so cautiously

First and foremost let me explain that the thread's title was a bit over the top. I was very excited to get these bullets in and they were sent much faster than I had hoped for so when I got home and saw a box on the doorstep I was stoked. I do intend to proceed in a patient and calm fashion as reloading and shooting firearms DEMANDS this be the way forward.

Secondly, thanks for the cautionary advisements - they are well received and appreciated and hey I gotta say that I am probably "Junior to the Junior" when it comes to direct reloading experience. I can assure you that I want to keep my face, arms, hands and fingers and the advice on here is add insurance towards that end.

Lastly, the advisements prompted me to visit Cabelas and look through 7 different reloading resources (all current versions) and there was ZERO load data on this bullet weight in this caliber. I called Speer and talked with their technician this morning that he says they have no published data at this time for the Grendel in ANY bullet weight. We did discuss that these bullets are coated and that the effect on pressure should be a reduction in pressure build as opposed to a negative effect, he equated the bullet to moly coating but it is a different process by which they are formed. So I looked through this forum (the heavy weight bullet thread) and extracted the following data from the six pages of posts:

18" LW barrel, Using 30.3grs H-380 and 139gr privi bullets getting 2305 FPS - FINE

barrel length unknown - 140 gr Gamekings loaded with 30.5 gr of LVR - States to be a little hot recommends grain less

Speer Hotcor 140 gr SP Over 24.4-24.7 grn. Tac - FINE

140gr Lapua Naturalis - H4895 @ 26.4 grs getting 2240 FPS - FINE

140 VLD with 29.1grs of AA 2520 unknown FPS - FINE

RL-15 and a 140gr Lapua Scenar. 27.2grs giving 2335 FPS out of a 24" tube - FINE

25.0gr of 8208 with aa brass cci primers at 2.265 oal and getting consistent 2350 fps out of a 24" lothar waltHer bbl - FINE

140gr Speer bullets 26gr of AR-Comp - Recommendation

So on the surface it would appear that I am below the levels of powder weight being loaded in other 140gr varieties tried by this user community AND that the bullet I am shooting is coated.

The wildcard at this stage is what powder is within the AA factory ammunition for the 129gr SST and how will it react to the heavier bullet.

I am going to give this a go, with the feeling that I have put in my due diligence to protect myself and I am also going to make the disclaimer DO NOT TRY THIS.

More to come later (hopefully)

BB

[LRRPF52]

I would just say to focus on determining if the load is safe, not focus on how accurate it is. That said, I would load one round in the magazine at a time to prevent you from getting excited and shooting a 3-round group, not knowing what the case looks like. Have a good plan for your brass catcher, so you can immediately see the case, not have to go looking for it. I use a large box placed right next to the right side of the rifle, held down by one of the carpeted bench boxes at one of my local ranges if I'm not using an actual brass catcher.

A chronograph is probably the best tool for checking pressure signs from shot-to-shot, since you will see any drastic velocity changes. When I see those, I stop with that load. Depending on what powder you have, you're probably ok, but I guess we'll find out. The action will usually take one high pressure load, like a test load, but starts to head into catastrophic failure mode after that.

[Bennybone]

Project aborted -

BB