New rifle (T3), new calibre (.22-250), new tool (OAL Gauge), new confusion

[Miki]

Just starting to reload my .22-250 with 55gn Sierra Blitzkings and using my new Hornady OAL guage.

So I check the length to the lands using the gauge and a comparator to find it is 2.172" (3.172 - 1" for the comparator). I set the OAL to 2.132", allowing 40 thou and notice that the bullet is well out of the case. Measuring the seating depth it's only 5.88mm, which as the bullet is a boat tail, is only 5mm ...

This seems wrong to me as all the measurement I can find on t'internet seem to indicate around 11mm of the bullet in the case. The case is the right length (1.901), am I doing something stoopid ??

Any T3 reloaders like to share their numbers ??

 

[Eric the Red]

My OAL is 2.353". This is with 50gr VMax.

Check the T3 max magazine length as you may need to load to that.

Your measurements seem very short? Your OAL is nearly 0.2" shorter and yet you feel the bullet is seated too far out? I do not believe 11mm of bullet in the case - a VMax is only 19.6mm long - so unless you have a measurement for a long VLD or something the two things don't tie up.

I always measure off the ogive for consistency too - mine (for max magazine length) is 49.78mm to ogive.

HTH

 

[Miki]

The Sierra bullet is 20mm long tip to tail.
The 11mm of bullet in the case I have picked up from the case length (1.902") to the max length of 2.30" - or 48.56 to 58.42 = 10mm - bullet = 20mm = 10/11 in the case.

I've obviously measured something wrong, because from tip to primer i'm at 64mm long..... i'll sleep on it and try again tomorrow - thanks for your answer

 

[Muir]

Want to save some headache? Load to recommended OAL or magazine length if that works. This obsession with the lands causes a lot of lost sleep! It is not a requirement for accuracy. Ask anyone with a 300AAC Blackout. Most can develop 1/2 MOA loads with 110 grain bullets in a rifle throated for 240 grain bullets. That's a lot of jump.

When i teach people to reload, the subject of measuring to the lands never brought up... by me at least.~Muir

 

[JTO]

Are you confusing OAL with Base-to-Ogive(BTO) length?

 

[takbok]

Throw away the OAL gauge and buy a reloading manual - it will save you a lot of hassle.

Here's plenty of reloading data, including the Sierra data:

http://m-b-r.co.uk/HTML/CalibreRelaodingInfo.php

 

[Orion]

Want to save some headache? Load to recommended OAL or magazine length if that works. This obsession with the lands causes a lot of lost sleep! It is not a requirement for accuracy. Ask anyone with a 300AAC Blackout. Most can develop 1/2 MOA loads with 110 grain bullets in a rifle throated for 240 grain bullets. That's a lot of jump.

This ^

Almost exactly mirrors my experience with the 300BLK - sub MOA with the 110 V-Max and just over with the 220gr SMK subsonic. And a big difference in OAL.

Throw away the OAL gauge and buy a reloading manual - it will save you a lot of hassle.

And this ^

https://www.google.co.uk/url?sa=t&r...ds.pdf&usg=AFQjCNFzwOUACqmZ3nVDRBG6Mat4xl_v6Q

 

[Miki]

Are you confusing OAL with Base-to-Ogive(BTO) length?

Could be .... (new tool this OAL gauge).

 

[Miki]

Want to save some headache? Load to recommended OAL or magazine length if that works. This obsession with the lands causes a lot of lost sleep! It is not a requirement for accuracy.
.~Muir

I'm coming to this conclusion

I do have a book (Lyman 50th). There is a section (p105) that mentions bullet seating depth and shows a picture with three 22-250 rounds. The chapter describes/the authors explains that his rifle exhibited better accuracy when he was back off the rifling between .03 and .1" - there is also a picture showing 3 rounds where the bullet is "barely held in the neck", the second "has a length of 2.43, seating the bullet sufficiently in the neck" and a third showing the .22-250's maximum cartridge length of 2.35"

There doiesn't seem to be any fuller/detailed explanation of "sufficiently deep in the case".

The cartridge drawing shows a max length of 2.350" (tip to base), a case length of 1.912", it is from this that I reasoned that the/my bullet of 0.78" (20mm) in length should be seated in the neck by (2.350 - 1.912") .438 ( = 11.12mm)

This is where i'm getting confused, the guage indicates that to be 50thou off the lands (start of the rifling) then my bullet is only 5.8mm inside the neck which means i'm 'way over' the maximum cartridge length - which (everywhere I look) is 2.350" (59.69mm)

 

[Flash9919]

Bullet should seated into the neck by a minimum of it's calibre....ie a .223 tip should be seated a minimum of .224" into the case....don't know if that's of any help?

 

[Orion]

This is where i'm getting confused, the guage indicates that to be 50thou off the lands (start of the rifling) then my bullet is only 5.8mm inside the neck which means i'm 'way over' the maximum cartridge length - which (everywhere I look) is 2.350" (59.69mm)

Which might lead you to load to book OAL instead of trying to chase the lands? Have you already worked up the load in terms of best powder and charge weight and primer before experimenting with bullet seating depth?

 

[Muir]

I'm coming to this conclusion

I do have a book (Lyman 50th). There is a section (p105) that mentions bullet seating depth and shows a picture with three 22-250 rounds. The chapter describes/the authors explains that his rifle exhibited better accuracy when he was back off the rifling between .03 and .1" - there is also a picture showing 3 rounds where the bullet is "barely held in the neck", the second "has a length of 2.43, seating the bullet sufficiently in the neck" and a third showing the .22-250's maximum cartridge length of 2.35"

There doiesn't seem to be any fuller/detailed explanation of "sufficiently deep in the case".

The cartridge drawing shows a max length of 2.350" (tip to base), a case length of 1.912", it is from this that I reasoned that the/my bullet of 0.78" (20mm) in length should be seated in the neck by (2.350 - 1.912") .438 ( = 11.12mm)

This is where i'm getting confused, the guage indicates that to be 50thou off the lands (start of the rifling) then my bullet is only 5.8mm inside the neck which means i'm 'way over' the maximum cartridge length - which (everywhere I look) is 2.350" (59.69mm)

The only tools you need are the loading manual and a good vernier caliper. Don't sweat the ogive. Don't worry that with some loads the OAL won't be exactly the same. Seat one to the depth listed in the manual, set your dies and seat the rest. Don't measure every round. They will still shoot well IF you have done the rest of your work (Case prep, etc) correctly.~Muir

 

[JTO]

My 284W rounds have an OAL of 3.233 inches with 180 Berger hybrids, using the BTO measurement for reference.
All three manuals that I have, show an OAL of 2.800 inches.

 

[Sinistral]

Just starting to reload my .22-250 with 55gn Sierra Blitzkings and using my new Hornady OAL guage.

So I check the length to the lands using the gauge and a comparator to find it is 2.172" (3.172 - 1" for the comparator). I set the OAL to 2.132", allowing 40 thou and notice that the bullet is well out of the case. Measuring the seating depth it's only 5.88mm, which as the bullet is a boat tail, is only 5mm ...

This seems wrong to me as all the measurement I can find on t'internet seem to indicate around 11mm of the bullet in the case. The case is the right length (1.901), am I doing something stoopid ??

Any T3 reloaders like to share their numbers ??

Your measurements seem off to me.
The Tikka magazine has an internal length of 2.400”/61mm, and the chamber has an even longer throat. In fact I tried every bullet shape in Hornady & Sierra from 50–60grs in weight & wasn’t happy with any of them. The industry favours the sexy combination of a long needle-shaped nose with a boat-tail. This produces a barrel-shape which gives only the option of deep seated bullets & a short OAL. In .22cal boat-tails don’t offer much benefit.

Nothing sparkled until I tried the Sierra 63gr SMP. This has a long parallel section, so seats to the neck base & out to the wall of the magazine with minimum ‘jump’. It will work with IMR 4895, IMR 3031,Vit N135,Varget, and slow ones like Nobel 0 & IMR 4350.
There’s no law which says you have to stick to medium-fast powders or lightweight pointy bullets with a .22-250. I’d recommend trying this one.

 

[Miki]

Bullet should seated into the neck by a minimum of it's calibre....ie a .223 tip should be seated a minimum of .224" into the case....don't know if that's of any help?

That makes engineering sense - an M8 bolt needs to be 8mm in the thread. .224" = 5.69mm so I should be good to go

 

[Miki]

Your measurements seem off to me.
The Tikka magazine has an internal length of 2.400”/61mm, and the chamber has an even longer throat.<snip>

Somethings odd, your not wrong

Me most likely

 

[PeterH]

Miki - you have bought an AOL gauge so why not use it. I assume with you deducting 1" for the comparator, you are using a dial caliper? I know a comparator length can vary but as a guide mine with bushing attached is 1.252" and without bushing is .9975"


I reload for a couple of T3 Super Varmints in 22.250 but only with the 55 gr Vmax so the following is once again only a guide as no doubt Sierra and Hornady in the same weight have differing ogive measurements.


T3 ogive to lands 2.089" COL 2.490"
T3 do 2.087" COL 2.488"

Not helpful to your cause is that my R93 in 22.250 with these Vmax has these measurements:
Ogive to lands 2.178" and are then seated 222 thou back at 1.956" and if I do my bit will shoot .25 to .3 no problem


Personally I would suggest you seat your bullets at an ogive reading of 1.955" or thereabouts - 120' ish thou back (this is more or less SAAMI spec) and if the powder and your case prep is good they should shoot well with only a very slight adjustment off the lands if at all.

 

[Miki]

Orion said

Have you already worked up the load in terms of best powder and charge weight and primer before experimenting with bullet seating depth?

No not yet, this is me starting...

I was looking at the 'One Book, One calibre' manual I brought back from the US earlier this year. The cal, rifle, tools and load are all new to me.
The manual gives me 5 loads using N140 from 32.9 up to 36.8gn with the specific bullet I have (Sierra 55gn B-King).

The Hornady guage manual tells me how to measure (am ok with that) and that I should set the bullet back into the brass (away from the lands) by between 40 to 50 thou.

The confusion washed over me when the difference between this advice (50thou back) and the COL stated in the manual became apparent when I used my new gauge and seated a bullet in an empty case and measured the overall length - which was considerably longer than the 2.350" COAL that the manual states - the bullet is 'hanging out there'.... looks completely wrong.

Having read what you have all said I have seated the bullet so that the overall length is 61mm, 1mm longer than the book COAL and some 2.85mm shorter than the Hornady guage/manual suggests (ie. 50thou backed out). It 'looks' right (well seated) and I feel comfortable, albeit still somewhat confused by what the Hornady gauge/manaul tells me...

When I have the grouping i'll change the charge (bringing me closer to the max and min) and figure out which is the best then i'll move the bullet in by 1mm and out by 1mm to see if that makes any difference.
Of those 12 variables the tightest group wins until either I run out of N140 and/or bullets at which point i'll change or if the rifle and I like one of those i'll stick with it.

 

[Miki]

Bit more info/reasoning (with pics)

Fist pic is where I am at the moment

View attachment 86338

At 61.12 this is shorter than the Hornady guage COL and shows a loaded round between the jaws of my caliper with a bullet. The bullet is also touching the left jaw showing the seating depth which puts the boat-tail/shank inside the case.

The second picure is (IMO) the maximum COL I can acheive with this round where the shank is fully seated into the case neck (offering the maximum concentric seating). This configuration will still place the bullet 1.85mm behind the lands (rather than the Hornady optimal 1.2mm)

View attachment 86339


Both configurations are longer than the book COL of 59.7mm (2.230")
Comments, critisism, stop ****ing aboot and shoot ?? (actually I think Muir has already said that - but in a far nicer way)

 

[Eric the Red]

Load to factory length and shoot it til you're pushing to close the groups. This aspect means nothing til you've got the charge right. I found N140 a little slow for my taste, but I may go back to it if forced to by supply.