Bullet jump for first loads.

[MalleeFarmer]

Ok so I have loaded up a dummy round on the lands for my 6slr. My question is where is the best place to start from for my first loads? I was thinking .005 off the lands? But is this too far off? Should I be starting say .002 thou and working back once I have a load?

[Apollo]

There are a couple of schools of thought here. Start off the lands to be safe and not cause pressure spikes or jam the bullet 0.010" odd.

In competition shooting the advice by one very experienced target shooter was to take numerous measurements and seat bullets 0.002" off the lands and work up a load. On the other side my Gunsmith has the opinion of jam the bullets 0.010" or more and work up a load. His view is that you have only one direction to go to adjust seating depth and that is progressively shorter. If you start off the lands you can go two directions so which do you pick first.

At first I went with the 0.002" off the lands and ended up with a very accurate load. In fact it was pretty stable at a tad over 0.10 MOA @ 100m. Tested numerous times at 200m to produce 5 shot groups between 0.2 & 0.25". The load stayed at that seating depth off the lands by chasing the lands ie remeasuring and adjusting longer as the throat wore.

These days I tend to soft seat bullets. ie not a great deal of neck tension (bushing dies), seat the bullet 0.020" longer and let the lands push the bullet back into the case (soft seating).

This applies to target rifles only where you are not going to extract a live round.

[MalleeFarmer]

Righto. I might just start .002 off then since it's a varmint rifle and will be used in the field and there's always the possibility of not firing once the bullet is fed into the chamber also I would prefer enough neck tension since they're going to be magazine fed.

[Chronos]

As Apollo said but I don't lie .002" off, it's a bit no mans land as if your seating stem isn't correct for your bullets you could get a few thou variation in seating depth. Now you've got one bullet that's touching and another that's 5 thou off. That'll give more variation in pressure than say one that's 10 thou off and another that's 15 thou off


What bullets are you using? I've found VLD style bullets are much more sensitive to seating depth than a hunting style bullet. With anything VLD I just start with load testing seated 5-10 thou off and shoot .3-.5 grain steps to find where the nodes are then pick the node i want. Then I do what Berger recommend in this article keeping in mind that pressures would be higher in the jammed loads so be careful if you're at a high node (I've never bothered with jammed loads yet)

http://www.bergerbullets.com/vld-making-shoot/

Chronos

[MalleeFarmer]

I'm using the 105gr A-Max and I have some 87gr V-max as well. as I couldn't get the 105 VLD or VLD hunting. Also I'm using a Whidden micrometer seating die.

[Gwion]

My amax load was all fire formed just on the lands and then I went 10thou out and found it worked well. I'd be looking at max mag length and compare that to max length touching lands. You may find you are limited to mag length and end up 50thou off.

I'm with Chronos in that 2thou is neither here nor there and found 5thou to be the same. 10thou seemed to be a good point for me. I've also experimented with the 'soft seating' and had good results but agree with you, it is not suited to a field load.

Summing up I found 10thou off or just on the lands to give me best results with the 7mm amax.

[Apollo]

Go with what you have and your plan. The big chance is that you will probably find your setting further from the lands than where you start testing.

Berger 105's aren't far away at any time so I wouldn't sweat too much. Keep an eye on BRT & Q-Store to see who gets them first and be quick. I'll be taking 1,000 as soon as I see them arrive even though I don't have a barrel chambered for the 6mm VLD's as yet. If I'm still waiting for the shipment then I know a few guys I can probably get 50 from to do load development.

Lapua Scenar are another choice but don't know what the supply is like in 6mm. I use 123gr 6.5mm Scenar for the time being until I can afford a re-chamber and use the newer 130gr VLD's again after Berger reduced the length by near 0.090" and stuffed my accuracy in my very long throated barrels.

I was given some A-Max one time and it didn't take long to work out why they were free. Dimensions were all over the place compared to Berger or Lapua so I gave them away as well to someone that didn't want them for competition shooting.

I shoot a .243W (Factory Class) but for accuracy with my restricted factory 1:10 twist barrels I found that the Berger 90gr BT Target were the most accurate and gave me a 1st Place in a 300m Fly Shoot. I also use them for varminting so I only needed to develop one load. I do not advise this to the unwary but my loads are jammed 0.020" soft seated but I have not had a problem yet removing a live round (carefully) if for some reason I didn't shoot it. If I used more neck tension and actually jammed the bullet in the lands it might be a different story.

I would not give my rifles to anyone else that wasn't experienced as also the triggers are very light at much less than 8ozs and in one case about 2ozs set mode..ie keep you finger well away from the trigger unless you intend firing immediately. I don't hunt, varminting from a fixed position and rest / bipod with these and I love it with a crisp light trigger.

[Chronos]

Go with what you have and your plan. The big chance is that you will probably find your setting further from the lands than where you start testing.

Berger 105's aren't far away at any time so I wouldn't sweat too much. Keep an eye on BRT & Q-Store to see who gets them first and be quick. I'll be taking 1,000 as soon as I see them arrive even though I don't have a barrel chambered for the 6mm VLD's as yet. If I'm still waiting for the shipment then I know a few guys I can probably get 50 from to do load development.

Lapua Scenar are another choice but don't know what the supply is like in 6mm. I use 123gr 6.5mm Scenar for the time being until I can afford a re-chamber and use the newer 130gr VLD's again after Berger reduced the length by near 0.090" and stuffed my accuracy in my very long throated barrels.

I was given some A-Max one time and it didn't take long to work out why they were free. Dimensions were all over the place compared to Berger or Lapua so I gave them away as well to someone that didn't want them for competition shooting.

I shoot a .243W (Factory Class) but for accuracy with my restricted factory 1:10 twist barrels I found that the Berger 90gr BT Target were the most accurate and gave me a 1st Place in a 300m Fly Shoot. I also use them for varminting so I only needed to develop one load. I do not advise this to the unwary but my loads are jammed 0.020" soft seated but I have not had a problem yet removing a live round (carefully) if for some reason I didn't shoot it. If I used more neck tension and actually jammed the bullet in the lands it might be a different story.

I would not give my rifles to anyone else that wasn't experienced as also the triggers are very light at much less than 8ozs and in one case about 2ozs set mode..ie keep you finger well away from the trigger unless you intend firing immediately. I don't hunt, varminting from a fixed position and rest / bipod with these and I love it with a crisp light trigger.

talk is the berger 105's will be around $63/100 and i just sold 200 scenars for $180 so it's not like it used to be. I've run out of 105 VLD's and with nothing available I've bought a 500 95gr VLD's and a few thousand Sierra 107's so I'll have to start to work on a load for them.

Chronos

[Apollo]

Wow, $90/100 for Lapua Scenars. I'd better find out from the LGS what my next 500 Bulk Pack is going to cost. At least if they are ordered and put on back-order the price is fixed at the current rate. Last time I bought Scenars I think they were half that in a bulk pack.

95gr VLD's do not work in my 1:10 Twist due to the bullet length, not weight.

They are all going up all the time at present (US$ conversion) so hope our dollar improves more as it is doing at present for when the next shipments get paid for. I think the last lot of 130gr 6.5mm VLD's were near $70 per hundred. Glad they weren't for me and double glad I have a few thousand of those in reserve. More fun to come weight sorting and then Moly Coating when the warm weather returns.

[Chronos]

Wow, $90/100 for Lapua Scenars. I'd better find out from the LGS what my next 500 Bulk Pack is going to cost. At least if they are ordered and put on back-order the price is fixed at the current rate. Last time I bought Scenars I think they were half that in a bulk pack.

95gr VLD's do not work in my 1:10 Twist due to the bullet length, not weight.

They are all going up all the time at present (US$ conversion) so hope our dollar improves more as it is doing at present for when the next shipments get paid for. I think the last lot of 130gr 6.5mm VLD's were near $70 per hundred. Glad they weren't for me and double glad I have a few thousand of those in reserve. More fun to come weight sorting and then Moly Coating when the warm weather returns.

$90/100 is cheap. They're $108/100 on the open range website

Chronos

Edit: I should point out I bought the 95's for my 1:8" twist 6BR for 300m shoots, I think the 107's are a better choice for 500m

[Apollo]

Sorry, my bulk box of 6.5mm is 1,000 count. Thought it looked a bit big.

The Open Range is very expensive since there are others selling them in stock for $70 odd and bulk for about $640 plus postage. Still both are dear compared to Berger which are more consistant in size and weight. I think those dearer prices might be the Scenar-L version. When Q-Store had the standard ones recently they were $56/100.

Pretty much what happened when the LGS was selling Berger at twice the going price.

Anyway, this is all off topic so I'll leave it alone until I have my 6BR in action and ready to test.

[MalleeFarmer]

My amax load was all fire formed just on the lands and then I went 10thou out and found it worked well. I'd be looking at max mag length and compare that to max length touching lands. You may find you are limited to mag length and end up 50thou off.

I'm with Chronos in that 2thou is neither here nor there and found 5thou to be the same. 10thou seemed to be a good point for me. I've also experimented with the 'soft seating' and had good results but agree with you, it is not suited to a field load.

Summing up I found 10thou off or just on the lands to give me best results with the 7mm amax.

I'm pretty sure on my 6slr touching the lands still fits in the standard Internal mag so I could always load them onto the lands and try that.

I'm not really experienced at this and I'm not sure what works best but I know I can't jam them and soft seating isn't ideal for field work.

I guess if I know my max seating length is on the lands so I don't get stuck projectiles and I start there and work back it would be a "field" approach to apollos idea of jamming them .010" and working back.

[Gwion]

Only reason I fire formed on the lands was to centre the cartridge in the chamber on the first shot so that the case expanded evenly. Theoretically, if you just neck size, the rounds will then chamber with the bullet in better alignment with the bore.

Best group on the lands for me was just on or just over 1/2"@100m, best at 10thou off is around <1/3"@100m.