Tikka T3 .243 short throat???

[nun_hunter]

Something I've noticed as my reloading has gotten more in-depth is that the bullet I'm using is pretty much jammed into the rifling/lands even under SAAMI max by quite some way.

I'm using 85grain game kings (HPBT but not especially long) and at the Sierra OAL of 2.650 there is a noticeable marks where the lands have scratched/marked the bullets once they're chambered. I tried to bring the OAL DOWN TO 2.610 as per Lyman manual but still marks there so I measured the marks and seated the bullets so they wouldn't be able to reach the lands at an OAL of 2.580 but there are still marks there.

Has anyone else had an issue with the throat on their rifle being so short as to have the bullet co tact the lands even when considerably under SAAMI max OAL?

I took a picture of the marks but it's not great in quality or focus. The marks aren't caused by chambering or extracting as I've tried this by hand and makes no difference plus on the 2.650 OAL rounds it was an obvious 5 (I think 5) evenly spaced marks that funnily enough coincide with the spaces of the rifling.

I should add thus round shoots superbly in my rifle and I've had no issues with rounds not chambering or bullets getting stuck etc. I imagine it's giving me a pretty consistent start pressure but not sure how safe or good for the rifle this is as it is for hunting as rounds are often chambered and unloaded multiple times.

 

[nun_hunter]

View attachment 85332

 

[Tis1979]

If your happy with the projectile and it shoots great then really there's no issue if there's no pressure signs, the only thing could be when your out in the field and the projectile jams in the lands and stays there when you remove the case you now have a stuffed trip.
so if you want it longer or you think you may use different size or type projectile that could cause an issue have a gunsmith ream the throat to a measurement your happy with.

good luck with it

 

[NigelM]

Tis is bang on.

I'm not a fan of jamming. Too easy to chamber a round, remove from the chamber to find the bullet stuck in the lands and powder running into the mag box.

Your options are either to load your bullet deeper into the case (which will increase pressure so you might want to drop charge weight to start with) or to get your chamber throated a bit deeper.

I have just put my 6.5 Lapua in to have 125 thou of freebore added so I can load 130 grain bullets without taking up too much case capacity. I was measuring 2.675" COAL to the lands and will go to 2.800".

 

[nun_hunter]

I'm planning to rebarrel it in a 6.5 when fund's allow so I cant really afford to have it worked on so think I'll pull the rounds I currently have and then load more to a shorter OAL and start some new development.

Think I'm more surprised that I didn't really notice it before (or realise the possible impmications) and they it'd come from the factory with such a short throat.

 

[NigelM]

Which 6.5 are you looking at?

When you do it buy the dies in advance and load a round up to the bullet and COAL you want, give it to the gunmaker and tell him you want it throated to that. Just make sure your twist rate will stabilise the bullet and you are short enough to go to a lighter, shorter bullet if you need to.

 

[nun_hunter]

Creedmoor is the plan. Good advice re making the round up first. I plan on using 140s (possibly the 143 ELD-X) so anything shorter should still work with a bit of a jump.

 

[NigelM]

Make sure you twist is at least 8, even 7.5 to be safe with the ELD-X. They are very long bullets. My 6.5 Lapua is 8.5 twist and it doesn't like them. All the more reason to load a blank round up, but make sure it still fits in the mag!

 

[Malxwal]

Nigel, which ELD-X have you tried ? Mine is 8.5, but I tend to stick to 123gr Scenars or Amax, 130 Bergers work too.

 

[NigelM]

143. Now on 130 Sciroccos and they are working well. Significantly better on Reds than the 120 Nosler BT's I have been using. A bit fiddly on seating depth but at 60 thou off the lands they are spot on.

 

[Malxwal]

143. Now on 130 Sciroccos and they are working well. Significantly better on Reds than the 120 Nosler BT's I have been using. A bit fiddly on seating depth but at 60 thou off the lands they are spot on.

Cheers Nigel, always good to hear actual experiences of bullet performance. Funny, boys using 47 round these parts swear by the Nosler 120 BTs for flattening reds.

 

[NigelM]

Cheers Nigel, always good to hear actual experiences of bullet performance. Funny, boys using 47 round these parts swear by the Nosler 120 BTs for flattening reds.

They have worked fine out to 200 yds, but much beyond that they have been average. I switched to 280AI for a while which sorted the issue out but having now sorted out the Scirocco 130 the Lapua is just fine. Run the ballistics and it is carrying the same energy at 300 yds as a 270 due to the BC of .575. Very little recoil and heaps of energy at distance - what's not to like?

 

[Primate]

Something I've noticed as my reloading has gotten more in-depth is that the bullet I'm using is pretty much jammed into the rifling/lands even under SAAMI max by quite some way.

I'm using 85grain game kings (HPBT but not especially long) and at the Sierra OAL of 2.650 there is a noticeable marks where the lands have scratched/marked the bullets once they're chambered. I tried to bring the OAL DOWN TO 2.610 as per Lyman manual but still marks there so I measured the marks and seated the bullets so they wouldn't be able to reach the lands at an OAL of 2.580 but there are still marks there.

Has anyone else had an issue with the throat on their rifle being so short as to have the bullet co tact the lands even when considerably under SAAMI max OAL?

I took a picture of the marks but it's not great in quality or focus. The marks aren't caused by chambering or extracting as I've tried this by hand and makes no difference plus on the 2.650 OAL rounds it was an obvious 5 (I think 5) evenly spaced marks that funnily enough coincide with the spaces of the rifling.

I should add thus round shoots superbly in my rifle and I've had no issues with rounds not chambering or bullets getting stuck etc. I imagine it's giving me a pretty consistent start pressure but not sure how safe or good for the rifle this is as it is for hunting as rounds are often chambered and unloaded multiple times.

I had exact problem this with my Tikka .243 Super Varmint using the same bullets. I was measuring off the Ogive and had a super accurate load seated at 2.2750. Unfortunately the Sierra's were jamming in to the point where I was pulling bullets out leaving them stuck up the spout. I was carrying a cleaning rod around in the motor when out stalking or lamping to tap em out when a round stuck in it! I went back to the bench and tweaked the load creeping in deeper and deeper, whilst testing for them sticking. I settled at 2.2400 off the ogive. Around 500 rounds later I've never had one stick in since. I put it down to the shape of the 85g BTHP and them being a blunt shape. I also have a very accurate load in the same rifle for 90 Nosler Bt's seated at 2.2640 these never stuck in, I think it because of the shape/profile (more pointy?) Have a play with your depth, I'm sure you will suss it like I did without losing any accuracy.
Cheers.

 

[nun_hunter]

Thanks for that comment and I'm sure I'll find a length that will work and will hopefully still be as accurate. The 95 grain SST never marked but similar to you and the Noslers they are more pointy and have a flat base to the base to ogive length is much shorter.

 

[Yorric]

Over the last few years I´ve seen quite a´few cases of massively high pressure caused by jamming 243 bulets into the lands. It seems to be more common in 243 than other calibres. I always recommend backing off the lands giving the extra safety tolerance.
I always check a new rifle that I am loading for with a Hornady gauge with modified case & the actual bullet to be loaded. - It is best to know that a new bullet loading will not have that chance of a pressure spike by being jammed into the chamber before I pull the trigger.
My mantra is wherever possible measure before you start as thereby you stay safe(r).

Ian

 

[nun_hunter]

All good advice and I'm learning more each day, just wish I knew more when I started. Anyway this eve I've loaded a few more test batches with an OAL of 2.555 which keeps the bullet out the lands by a fair way and it isn't too far past the neck/shoulder junction. Fingers crossed one of them shoots as well as the old ones.

I should add I'm also crimping these bullets after reading the thread on neck tension and some wise words from Muir. My logic at least it that I was getting uniform start pressures due to the fact the bullet was touching the lands. Hopefully the crimp will go some way to duplicate this.

 

[Yorric]

IMHO light crimps are good.
Heavy crimps are bad. Especially on thin,soft walled target bullets, as they easily deform too much.
The question is what is heavy & what is light? I use the imprint of my crimping die on the case neck as my gauge, along with the 'feel'.

Ian

 

[MarkT]

Something I've noticed as my reloading has gotten more in-depth is that the bullet I'm using is pretty much jammed into the rifling/lands even under SAAMI max by quite some way.

I'm using 85grain game kings (HPBT but not especially long) and at the Sierra OAL of 2.650 there is a noticeable marks where the lands have scratched/marked the bullets once they're chambered. I tried to bring the OAL DOWN TO 2.610 as per Lyman manual but still marks there so I measured the marks and seated the bullets so they wouldn't be able to reach the lands at an OAL of 2.580 but there are still marks there.

Has anyone else had an issue with the throat on their rifle being so short as to have the bullet co tact the lands even when considerably under SAAMI max OAL?

I took a picture of the marks but it's not great in quality or focus. The marks aren't caused by chambering or extracting as I've tried this by hand and makes no difference plus on the 2.650 OAL rounds it was an obvious 5 (I think 5) evenly spaced marks that funnily enough coincide with the spaces of the rifling.

I should add thus round shoots superbly in my rifle and I've had no issues with rounds not chambering or bullets getting stuck etc. I imagine it's giving me a pretty consistent start pressure but not sure how safe or good for the rifle this is as it is for hunting as rounds are often chambered and unloaded multiple times.

Hi,
I found this after a rebarrel on my 243. The chambering was done to CIP spec and using 87grain Vmax couldn't get near max O.A.L length of 2.710 . However, 105 grain Amax achieve 2.762 at the lands and Sierra 95 grain TMK's sit even longer.
I think it may be down to bullet shape rather than throat length.
Happy hunting.

 

[User00033]

Over the last few years I´ve seen quite a´few cases of massively high pressure caused by jamming 243 bulets into the lands. It seems to be more common in 243 than other calibres. I always recommend backing off the lands giving the extra safety tolerance.
I always check a new rifle that I am loading for with a Hornady gauge with modified case & the actual bullet to be loaded. - It is best to know that a new bullet loading will not have that chance of a pressure spike by being jammed into the chamber before I pull the trigger.
My mantra is wherever possible measure before you start as thereby you stay safe(r).

+100

one of the most critical tools in the process IMO:
http://www.hornady.com/store/Lock-N-Load-OAL-Gauge-Straight-1Each/

I determined I had a max COAL of 2.650" in my Howa .243 in the store before I bought it, it was that important to me to know what COAL I could load to.... because as others have said above, it is quite common in .243 to have the problem you have described. Also, the comments above about jamming a pill into the lands and then having it stick - well that is a massive bummer and has ended many a hunt as the shooter cannot possibly get it out without a rod. It is happening more and more as guys switch to long tapered bullets without fully realising the risks of pushing into the lands. Back off by 0.010" minimum for a hunting load is my advice, only the BR guys need to be concerned with touching the lands.